The militants have fired the positions of the Ukrainian military in Donbas 77 times over the past day, the ATO press centre said on its Facebook page on Tuesday morning.

"As a result of hostilities over the past day, four Ukrainian defenders have been injured," a report says.

In the Mariupol sector, the militants fired rocket launchers near Bohdanivka, the staff said on Facebook. Ukrainian positions came under attack of 120mm mortars in the same area, as well as near Chermalyk and Krasnohorivka, the staff said.

In addition, the militants used 122mm tube artillery near Chermalyk. Attacks on Ukrainian army positions were seen near Vodiane, Shyrokyne, Pavlopil, Novotroyitske, Hnutove, Talakivka and Maryinka, where the militants fired small arms, grenade launchers and 82mm mortars on strongholds, Kyiv said.

There were three militants' attacks on residential areas in the Mariupol sector. Two mines blasted near homes in Krasnohorivka in the morning. A number of artillery shells fired by the militants blasted in a Pavlopil residential area later in the day. The militants hit a street in Maryinka with a mounted anti-tank grenade launcher's round at about 9 p.m. The attacks did not inflict civilian casualties, Kyiv said.

Meanwhile, Ukrainian army positions in the Donetsk sector came under 26 attacks of the militants. Tensions persisted in a suburb of Avdiyivka, where the militants systematically fired 120mm and 82mm mortars, tank guns and infantry weapons on Ukrainian army positions, Kyiv said.

In the Luhansk sector, the militants mounted several attacks by use of 120mm mortars on Ukrainian defense lines near Krymske, Kriakivka and Novotoshkivske, Kyiv said.