Amid a fragile ceasefire, eyewitnesses in the separatist stronghold of Donetsk have reported heavy artillery and shelling. The increase in fighting follows the sighting by observers of a large, unmarked military convoy.
Eastern Ukrainian separatists engaged in heavy fighting with Ukrainian troops near the city of Donetsk on Sunday.
Artillery was heard from outside the city and from the area near the airport, the site of numerous battles between the two sides, according to reporters from Donetsk.
Local authorities also criticized the Ukrainian forces of targeting a residential area. At least two rebel fighters were killed and another person injured when the Ukrainian military deployed barrel bombs, news agency DPA said, attributing the information to the separatists' deputy commander, Eduard Bassurin.
The news agency AFP further cited a statement on the website of Donestk's City Council as confirming the attack, adding that firefighters were on the scene. However, it did not verify whether the assault had claimed any lives.
OSCE sights convoy
Ahead of the increase in fighting overnight into Sunday morning, the Organization for Security and Cooperation (OSCE) spotted a large column of unmarked tanks, howitzers and troop carriers moving through eastern Ukraine.
The sighting of the large convoy came a day after Kyiv had accused Russia of sending tanks and heavy artillery over the border, an allegation which Moscow has denied.
The OSCE said the columns seen late on Saturday included 19 large unmarked "Kamaz" trucks towing 122mm howitzers and carrying military personnel in dark green unmarked uniforms. It also reported nine tanks moving roughly 7 kilometers (4 miles) southwest of the Donetsk city center.
Both Kyiv and pro-Russian separatists have accused each other of undermining the September peace accord. Last weekend, separatists held elections, a move deemed illegal by the West and by Kyiv as a direct violation of the Minsk agreement. Russian President Vladimir Putin has not recognized the results of the vote, instead opting only to comment that the self-proclaimed "Donetsk People's Republic" had the right to elect its leadership.
Although Kyiv has vowed to uphold the peace agreement, the military deployed more troops to eastern Ukrainian cities last week in anticipation of attacks by rebels.
Fighting in eastern Ukraine has claimed over 4,000 lives in the past six months and caused the largest rift in diplomacy between the West and Russia since the Cold War.
kms/nm (AP, AFP, Reuters)