In an apparent Muslim terrorist attack, a gunman opened fire on a U.S. Air Force bus outside Frankfurt airport Wednesday, killing two airmen and wounding two others. A source told Fox News that the shooter yelled "Allahu Akbar" - the Muslim battle cry - as he began firing. 

Kosovo's interior minister told The Associated Press that German police have identified the suspect as Arif Uka, a citizen of Kosovo from the northern town of Mitrovica. 
 
The bus was idling outside Terminal 2 at the airport, according to Frankfurt police spokesman Manfred Fuellhardt. The bus driver and a passenger were killed. One person suffered serious wounds and another light injuries, according to Fuellhardt. Uka then dropped his gun and  ran into the terminal where he was subdued.
 
Fox News quoted U.S. Air Force Europe spokeswoman Maj. Beverly Mock as saying all four victims were airmen based at the Lakenheath military base in Britain. A military official in Europe said they were going to be deployed to Iraq or Afghanistan.
 
A website named Pundit Press published a post in which it speculated that this is the attacker's Facebook page, although it admitted it does not have proof that this is the case and apologized in case it turns out to be wrong.
 
President Barack Obama said he was "saddened and outraged" by the shooting and vowed that the U.S. will spare no effort in finding out how the "outrageous" act came to pass.
 
German Chancellor Angela Merkel called the shooting "a terrible event."
 
A member of the U.S. House Homeland Security Committee, Rep. Patrick Meehan, said in Washington that the attack looked like a terrorist act. He added that he did not have all the facts about the shooting yet.
 
In 2007, German police thwarted a plot by members of the extremist Islamic Jihad Union to attack U.S. facilities.