When he opened fire, the gunman shouted "Allah Akbar," according to sources. He fired nine times, killling two and critically wounding two others before the gun jammed and he was subdued by other passengers. While being wrestled into submission, the suspect shouted either "Jihad Jihad" or "Allah Akbar," sources said.
See also: Shooting at Germany Airport Kills 2 U.S. Airmen
A man whose office is near the site of the shooting said it was an area where buses load arriving passengers. Speaking on condition of anonymity to protect his business, he said witnesses told him that the gunman first talked to the military personnel to find out who they were and then opened fire, shouting “God is great” in Arabic.
The gunman, Arif Uka, is a Kosavar from the town of Mitrovica
Were the Americans on this bus specifically targeted, or were they just targets of opportunity? Arif Uka had a gun at an airport. That suggest that something was planed, even if the particulars and details were not. An airport is a likely place to find Americans. His plan, if he had much of a plan at all, may have been to go to an airport, listen and watch for a large group of Americans - and then shoot them.
Terror does not have to be well planed or planed in much detail. It just requires the will to carry it out.