A German court sentenced a Kosovo man to life on Friday for killing two U.S. soldiers and attempting to kill three more at Frankfurt airport last March in Germany's first deadly jihadist attack.

Presiding judge Thomas Sagebiel said 22-year-old Arid Uka -- who was born in Kosovo but brought up in Germany -- was found guilty on two counts of murder and three counts of attempted murder when he opened fire on March 2 last year on a group of U.S. soldiers on their way to serve in Afghanistan.

German federal prosecutors said Thursday they suspected an "Islamist motivation" was behind the fatal shooting of two U.S. airmen on a military bus at Frankfurt airport.

"In view of the circumstances, there is a suspicion that this was an act with Islamist motivation," prosecutors said, as police questioned a 21-year-old suspect of Kosovan origin arrested after Wednesday's attack.