Frankfurt shooting suspect confesses to targeting US military

The revelation came as investigators probed what they consider a possible act of Islamist terrorism.

Hesse state interior minister Boris Rhein said the suspect, identified as a 21-year-old ethnic Albanian Arid Uka from Kosovo, was apparently radicalised over the past few weeks.

The German born-and-educated suspect opened fire on a US Air Force bus carrying 15 airmen, based at RAF Lakenheath in Suffolk, to Ramstein airbase.

Uka's family said he worked at Frankfurt airport and was a devout Muslim. He was taken into custody after the shooting.

"From our investigation so far we conclude he acted alone," Mr Rhein said. "So far we cannot see a network." He said police believe Uka had contact with other radicals on a social network site "but there is no network in the sense of a terror cell".

Uka's Facebook photo features a silhouette of Kosovo, with the phrase "There is no God but God and Muhammad is his prophet" written above it in Arabic. Mr Rhein said Uka recently changed his profile name to the nom de guerre "Abu Reyyan." On his page there are hate-filled rants against Jews and a cry for Jihad. It states: "If someone would call you to Holy War… yeah, and? That is part of this beautiful religion. One is allowed to fight the unbelievers when attacked."

"Germans are afraid of Islam and its spread and would rather we believe in Santa Claus," he rambles in one posting. He calls Chancellor Angela Merkel an "unbeliever" siding with Israel.

One US airman remains in critical condition after being shot in the head during the airport attack.

Near the suspect's father's home in Frankfurt, neighbours described Uka. "I do think he was religious, but he is just a normal young guy - completely normal," neighbour Katharina Freier said. "We were all shocked."

Kosovo is mostly Muslim, but its estimated two million ethnic Albanians are strongly pro-American due to the US's leading role in Nato's 1999 bombing of Serb forces that paved the way for Kosovo to break from Serbia.

Uka's uncle, Rexhep Uka, said the suspect's grandfather was a religious leader at a mosque in a village near the Kosovo town of Mitrovica, and that Arid Uka was a devout Muslim. But he also said the family was pro-American.

"I love the Americans because they helped us a lot in times of trouble," he said.

Behxhet Uka, a first cousin of the suspect, said he had spoken to the gunman's father.The family told him that all they knew was that their son did not come home on Wednesday from work at the Frankfurt airport.

"We heard about this from the local police," he said. "I would hope that this is not true. We could not imagine something like this would happen because Americans are our brothers."

Police said the attacker had an altercation with US military personnel in front of a bus at Terminal 2.

They said he started shooting, boarded the bus and was apprehended trying to escape.