For the last two months, the Donetsk People's Republic have been taking government buildings and attacking the Ukrainian military across the region with limited resistance as Kiev's anti-terror operation looks to avoid civilian casualties.
On Monday, it seems the DPR's move for the airport crossed a line and this time the Ukrainian army stood up to rebels and retaliated with extreme and at times merciless force.
The fighting at the airport was certainly the heaviest in eastern Ukraine since the crisis here started. The DPR, although well armed with experienced fighters, clearly weren't able to fight in a complicated contact scenario and deal with the Ukrainian forces air superiority.
The Battle for Donetsk International Airport: Watch our latest Russian Roulette here.
Early Monday morning, gunmen of the Donetsk Peoples Republic arrived at the airport and took over the terminal building, prompting the Ukrainian military based there to issue an ultimatum to the rebels to lay down their weapons and leave.
The ultimatum was not heeded however and a massive firefight broke out around 1pm in which both fighter jets and attack helicopters were used by the Ukrainian military.
Fighting in Ukraine escalates as Militia Groups flock to Donetsk. Read more here.
The sound of gunfire and explosions filled the air as rebels and journalists ducked for cover along the access road to the airport terminal. The next morning gunfire could still be occasionally heard but the situation still remained unclear.
Both sides claimed they controlled the airport, though it was clear that the Ukrainians had taken control and casualty figures were fluctuating, as more bodies were brought into the local morgues and were being identified.
From talking to police and DPR officials at the main Kalinina morgue, at least 33 DPR gunmen had been killed in the assault, while the government was claiming 150 perished in the fight.