This is a timeline of the war in Donbas for the year 2021.
January–March 1 January: The Ukrainian press centre of the Ukrainian Joint Forces reported nine pro-Russian violations of the ceasefire agreement on this date. In the eastern area of operations, the stronghold of Avdiivka received fire from small arms, automatic grenade launchers and 82 mm mortars. An incoming hostile drone that had taken off from Yakovliivka was neutralized by Ukrainian forces with electronic countermeasures. Vodiane, in the region of Pryazova (around Mariupol) was the target of small arms and anti-tank rocket fire. Small arms fire was also reported at Pavlopil. In the northern front, pro-Russian forces fired heavy machine guns and different grenade-launcher systems at Ukrainian positions around Zolote-4, while Ukrainian troops were harassed with small arms fire at Novoluhanske. Ukrainian forces fired back. 11 January: The Ukrainian Joint Forces press centre reported 11 pro-Russian attacks on their forces on this date. All the incidents occurred in the eastern area of operations. Ukrainian troops at Pisky received fire from small arms and heavy machine guns; one Ukrainian soldier was killed in action. Avdiivka and Pavlopil were hit by anti-tank rockets, and Avdiivka also received small arms fire. Small arms fire was also registered at Vodiane, as well as sniper fire in the surroundings of Donetsk city. A pro-Russian drone flying over Krasnohorivka was neutralized by Ukrainian forces. 25 January: The press centre of the Ukrainian Joint Forces recorded seven pro-Russian violations of the truce, most of them in the northern area of operations. Pivdenne became the target of heavy machine guns, anti-tank-rocket launchers, 120 mm mortars and anti-tank guided missiles. Nearby Vilnyi received fire from small arms, heavy machine guns, automatic grenade launchers and anti-tank rocket launchers. One Ukrainian soldier was wounded in action. 27 January: According to the Ukrainian Joint Forces press centre, pro-Russian forces launched ten attacks on their positions. In the eastern area of operations, Pavlopil became the target of small arms, heavy machine guns, grenade launchers and 120 mm mortars. Ukrainian positions at the protected area of Bohdanivka were hit by small arms fire, sniper and heavy machine gun fire, as well as anti-tank rockets. Under-barrel launched grenades were fired at Ukrainian troops in Vodiane, while automatic rifle fire was reported at Marinka and Avdiivka. Luhanske was hit by anti-tank rockets, and Zaitseve was shelled with automatic grenade launchers. There was return fire from Ukrainian positions. 22 February: The Ukrainian Joint Forces press center recorded 11 pro-Russian violations of the truce throughout the day. Two soldiers were killed in action and three wounded. In the eastern front, Ukrainian positions around Avdiivka were hit by different types of grenades and rockets; one serviceman was killed and another wounded in the area. The Ukrainian stronghold of Vodiane received fire from small arms, different grenade-launcher systems, POM-2 landmine launchers and 82 mm mortars. Marinka was hit by anti-tank rockets, while Ukrainian troops at Pervomaisk were harassed with small arms fire. In the northern area of operations, Pivdenne became the target of small arms, heavy machine guns and automatic grenade launchers, while later in the night, Zaitseve was hit by anti-tank rockets and 82 mm mortar volleys. One soldier was killed and another wounded. 24 February: The Ukrainian Joint Forces press center recorded six pro-Russian attacks on their troops. In the eastern area of operations, Avdiivka and Vodiane came under fire from automatic rifles and different grenade-launcher systems. Ukrainian redoubts near Marinka received anti-tank rocket fire, while small arms fire was reported at Talakivka. In Chermalyk, a Ukrainian sentry was wounded with a blade weapon when pro-Russian troops attacked his position. The sentry reacted, and a pro-Russian soldier was taken prisoner. In the northern front, Ukrainian troops at Pivdenne were harassed with automatic fire, and another Ukrainian serviceman was wounded. 26 February: The press center of the Ukrainian Joint Forces recorded an escalation in hostilities around the demarcation line on this date. Pro-Russian forces launched 14 attacks on Ukrainian positions. In the eastern area of operations, the Ukrainian stronghold of Vodiane was hit by 120 mm mortars barrages; nine Ukrainian soldiers were wounded. The area also received fire from small arms and different grenade-launcher systems. Pisky came under the combined fire of 82 mm and 120 mm mortars. Ukrainian positions in the area also became the target of small arms and heavy machine guns. Kamianka was fired at from small arms, automatic grenade launchers and anti-tank recoilless rifles. The explosion of a roadside bomb wounded a Ukrainian soldier near Nevelske. Small arms fire was reported at Marinka and Lebedinske. In the northern front, Luhanske was targeted by heavy-machine guns, snipers, anti-tank rocket launchers and POM-2 landmine launchers. Pivdenne and Svitlodarsk were attacked using small arms, automatic grenade launchers and anti-tank recoilless rifles. 26 March: The Ukrainian Joint Forces press center recorded four pro-Russian violations of the truce throughout the day. Four Ukrainian soldiers were killed and two others wounded in the afternoon when pro-Russian forces shelled Ukrainian positions with 82 mm mortars near the village of Shumy, in the area of Horlivka, in the northern front. The separatists also employed heavy machine guns and automatic grenade launchers. Ukrainian troops returned fire. The fighting was still ongoing by 06:00 pm. Ukrainian redoubts came also under automatic rifle and anti-tank rocket fire near Mayorsk, in the same area of operations. With the latest casualties the death toll in Eastern Ukraine since the beginning of the July 2020 truce reached 45 servicemen killed in action. Another 75 were wounded.
April–June
1 April: An escalation in hostilities was reported by the press centre of the Ukrainian Joint Forces, with 13 pro-Russian violations of the ceasefire on this date. In the eastern area of operations, Ukrainian redoubts around Pisky were shelled with 82 mm and 120 mm mortars. The strongholds of Avdiivka, Starohnativka and Vodiane became the target of small arms and different grenade-launcher systems. An anti-tank guided missile also landed in Vodiane. In the northern front, Shumy and Novotoshkivka received fire from automatic grenade launchers. Two Ukrainian servicemen were wounded in action. Pro-Russian forces fired small arms, heavy machine guns and anti-tank rocket launchers at Ukrainian positions near Svitlodarsk, Zolote-4 and Luhanske. Ukrainian forces fired back. 2 April: The Ukrainian Joint Forces press center recorded 21 pro-Russian violations of the truce throughout the day. Two soldiers were wounded in action. In the eastern front, Ukrainian positions around Krasnohorivka, and the villages of Pyshchevyk and Hnutove, were hit by 120 mm mortar volleys. A civilian resident was wounded at Krasnohorivka. An anti-tank guided missile landed in Opytne. Vodiane and Avdiivka received anti-tank rocket fire. Small arms fire was reported at Pisky. In the northern area of operations, Zolote-4 and Novooleksandrivka were struck by 82 mm and 120 mm mortar barrages. Ukrainian positions at Novotoshkivka, Novoluhanske and Svitlodarsk became the target of different grenade-launcher systems. Ukrainian troops at Novotoshkivke and Svitlodarsk were also harassed with machine gun fire. 5 April: The press centre of the Ukrainian Joint Forces recorded seven violations of the ceasefire by pro-Russian forces. Two Ukrainian soldiers were killed by gunfire. 6 April: A further escalation of hostilities was reported by the Ukrainian Joint Forces' press centre, with 14 pro-Russian violations of the ceasefire. Two Ukrainian soldiers were killed by pro-Russian separatists in eastern Ukraine amid escalating tensions and a military build-up along the border between Russia and Ukraine. 8 April: The Ukrainian Joint Forces press centre reported that pro-Russian forces violated the ceasefire agreement 15 times. A Ukrainian soldier of the 36th Separate Brigade of the Marine Corps, was killed by sniper fire from the pro-Russian forces in Donetsk region. Another Ukrainian soldier was also killed by artillery shelling near Luhansk. 9 April: The Ukrainian military used for the first time a Turkish drone Bayraktar TB2 for a reconnaissance mission over the Donbas. The drones had been delivered to Ukraine in June 2019. 10 April: The Ukrainian Joint Forces press centre announced they had recorded ten ceasefire violations, including small arms fire and mortar attacks. One Ukrainian soldier was killed and another was wounded due to the violations. 12 April: The Ukrainian Joint forces press centre said that they had recorded 17 ceasefire violations by Pro-Russian forces, leaving one Ukrainian soldier dead. In the northern area of operations, pro-Russian forces attacked Pivdenne with automatic rifles, anti-tank rocket launchers, 120 mm mortars and armoured fighting vehicles. Ukrainian positions at Shumy and Zaitseve received fire from small arms, heavy machine guns, different types of grenade launchers and 82 mm mortars. Pro-Russian armoured fighting vehicles, supported by anti-tank rocket fire, launched an attack on Ukrainian redoubts at New York. Zaitseve was meanwhile targeted with anti-tank rocket launchers and POM-2 landmine launchers. In the eastern front, small arms and heavy machine guns were fired at Pisky and Kamianka. 13 April: From midnight to 7 am, Pro-Russian forces were still conducting attacks in breach of the ceasefire agreement, including mortar attacks. One Ukrainian soldier was killed after a pro-Russian drone dropped several grenades on Ukrainian positions in the village of Mayorsk. Another two soldiers were wounded in this attack.NATO Secretary General Jens Stoltenberg called the new Russian build-up along Ukrainian borders "unjustified and deeply concerning". 18 April: The Ukrainian Joint forces press centre recorded eight ceasefire violations including attacks from mortars and grenade launchers, targeting Ukrainian positions. Ukrainian forces returned fire in response. During the attacks, one Ukrainian soldier was killed and another was wounded. 21 April: The press centre of the Ukrainian Join Forces recorded eight violations of the ceasefire by pro-Russian forces. In the eastern area of operations, 120 mm mortar barrages landed in Pisky. The village was also hit by anti-tank guided missiles. Kamianka became the target of 73 mm anti-tank recoilless rifles, while Krasnohorivka received fire from automatic grenade launchers. In the northern front, pro-Russian armoured fighting vehicles engaged Ukrainian redoubts near Novhorodske. Nearby Pivdenne was hit by anti-tank guided missiles and shelled with 120 mm mortars. Pro-Russian forces pounded Ukrainian positions at Shumy and Pervomaiske with heavy machine guns, automatic grenade launchers and 82 mm mortars.