By Rebecca Shabad - 04/15/14 11:56 AM EDT
Heavy gunfire was heard at an airport in eastern Ukraine on Tuesday after the government deployed troops in an effort to target pro-Russian separatists occupying parts of the region, according to the Associated Press.
An AP reporter heard the gunfire at a military airport in Kramatorsk. Ukrainian troops and the city’s mayor took over the airport and blocked the entrance, the report said.
Russian state news agency RIA Novosti reported Ukrainian soldiers wounded two pro-Russian militiamen near the airport. The AP said it couldn’t independently confirm the report.
RIA Novosti reported Ukrainian troops drove to the airport in an armored personnel vehicle, and a skirmish erupted after they spoke to the pro-Russian gunmen.
These developments come as Ukraine’s government in Kiev launched an “anti-terrorist” operation on Tuesday to root out the pro-Russian demonstrators who have gradually occupied government buildings and property in eastern Ukraine over the last week.
Busloads of Ukrainian troops and several army tanks were set up around the eastern city of Slovyansk, which is 100 miles from Russia’s border. Helicopters were also seen heading toward the city.
Pro-Russian gunmen seized control of the city last weekend, the AP said.
"We are awaiting the order to move on Slovyansk," one soldier said.
Pro-Russian militias have been occupying government, administrative and police buildings in at least nine cities in eastern Ukraine, where a majority of people speak Russian.
The United States has been watching this escalation closely, concerned that Russian President Vladimir Putin will annex eastern Ukraine as he did with the Crimean Peninsula in March.
President Obama spoke to Putin in a “frank and direct” phone call on Monday afternoon, according to a senior Obama administration official.
Obama expressed “grave concern” that Russia was supporting the pro-Russian armed militiamen.
Putin, however, denied those accusations, and said it was “speculation” that is “based on inaccurate information.”
Some lawmakers, meanwhile, have been pressuring Obama to impose much stronger sanctions against Russia’s economic sectors.