On Tuesday, the Ukrainian military launched an offensive against pro-Russian forces in eastern Ukraine. Russian media reports that four people were killed as Ukraine regained control of the airport in Kramatorsk during the "anti-terrorist operation," as Ukraine's acting president put it, though those numbers haven't been independently confirmed.

Russian Prime Minister Dmitry Medvedev warned that the offensive may lead more violence in the region, writing on Facebook: "Blood has once again been spilt in Ukraine. The country is on the brink of civil war."

But Ukraine's acting president, Oleksandr Turchynov, downplayed the risk of escalation.

"[The offensive] will be carried out in stages, and responsibly and in a balanced manner. The goal is the defense of citizens of Ukraine," he said in a statement. "Russian special forces and terrorists, there are hundreds of thousands of innocent Ukrainian people deceived by Russian propaganda, and that is why we will take any needed anti-terrorist actions prudently and responsibly."

Activists at the scene reportedly told Russia-owned RT that four people died during the conflict, but the Associated Press and the New York Times report that most of the "heavy gunfire" consisted of warning shots in the air.

From the New York Times:

A column of armored personnel carriers flying the Ukrainian flag entered the airport late in the afternoon, local reporters there said. The convoy was met by a crowd of pro-Russian militants that the soldiers tried to push back by firing in the air, they said. The Ukrainian soldiers quickly took control of the facility, while the commander sought to persuade the militants to leave, they said, describing the situation as more of a "mob scene" than a gunfight.

RT posted several videos and pictures from the scene, including one in which military jets can be seen flying over Kramatorsk.

[Image via AP]