The press center of the Ukrainian army's operation in the south-east has accused militants of again opening fire on positions held by the Ukrainian army in all parts of Donbas starting from 6:00 p.m. on June 1.

The press center claimed on its Facebook account on Tuesday morning that militants were allegedly firing mortars and artillery weapons with a caliber of over 100mm against the localities of Pisky, Mariyinka, Opytne, Vodyane and the Butivka mine in the Donetsk said.

"Near Artemivsk, Markove came under artillery fire, mortars were fired on Novhorodsk, large-caliber machine guns against Leninsky, and grenade launchers and small arms against Kirove. An armed clash with the adversary's reconnaissance group broke out near Vesela Hora," it said.

The press center also said the militants used mortars, artillery weapons, grenade launchers and small arms in attacks on the village of Shyrokyne near the city of Mariupol.

"However, the situation was quiet there after 9:00 p.m. up to this morning," it said.

The situation in the Luhansk region was also relatively calm, the press center said. Small arms were allegedly fired twice against Schastia and Zolote-4, it said.

Furthermore, drones were allegedly spotted on 15 occasions over the Luhansk region and Mariupol, the press center said.