Ukraine accused pro-Russian rebels on Monday of carrying out the heaviest artillery attacks on government positions in six months and warned of signs the conflict was escalating despite a cease-fire deal.
The military said 400 rebel fighters supported by tanks had attacked government forces around the village of Starohnativka, 50 km (30 miles) north of the Kiev-held port city of Mariupol. The rebels denied attacking government troops.
Control of Mariupol could help the rebels form a corridor to the Crimea Peninsula, which Russia annexed from Ukraine last year.