The battle for the crippled Donetsk airport has intensified once again, as pro-Russian rebels renewed attempts to break the Ukrainian forces grip on the complex.
At least six people were killed as explosions and heavy gunfire rung out across the airport, which has long ceased functioning after months of conflict.
With peace talks on ice, Kiev rushed troops to the airport which holds symbolic value for both sides in the conflict.
Ukraine maintained that they held onto its position, contrary to rebel statements that they had taken control of the site.
A meeting of representatives from Ukraine, Russia and the OSCE scheduled for Friday did not go ahead.
Getting the so-called contact group to sit down for talks is seen as crucial for getting both sides to observe a ceasefire that holds.