A man armed with a knife attacked passengers on a bus in northern Germany Friday before being taken into custody, authorities said.

An unknown number of passengers were injured, including one seriously, during the attack on the crowded bus in Luebeck, Germany, at about 1:47 p.m., authorities said. No one died, they said.

The suspect "was overpowered" and taken into custody, police in Germany's Schleswig-Holstein state said in a statement. He was a 34-year-old German national, Luebeck's chief prosecutor, Ulla Hingst, said, according to the Associated Press.

"There are no indications that the man was politically radicalized," police and prosecutors said in a statement. "There are also no indications at present of a terrorist background."

Police said many witnesses had already left the scene before they could speak with them. The bus was fully occupied, police said.

ABC News' Sarah Hucal reported from Berlin.