What could well be the first shots of a Ukrainian Civil War were fired today, as the military attacked the city of Kramatorsk as part of what they couched as an “anti-terrorist” operation against protesters seeking autonomy for the nation’s eastern region.

The Ukrainian military’s helicopter gunships attacked the small airport on the outskirts of Kramatorsk, while tanks moved to the area around the neighboring city of Slovyansk, which is largely under the control of pro-protester militias.

The primary fighting so far has been at the airport, however, where Ukraine’s Army reported at least one soldier wounded, and several reports have emerged of

at least four protesters killed. Some claimed the toll could be even higher, with as many as 11 slain.

Ukraine’s government reported the “liberation” of the airport later in the afternoon, along with a police station in the city. Protesters in Kramatorsk continued to condemn the offensive, demanding a referendum on autonomy.

By evening the reports are that the fighting had more or less ended, with the troops apparently taking their time in crushing the protests, and continuing to push for Western and UN aid for the invasion.