German media say police are searching for a Tunisian man, in connection with a deadly attack on a Christmas market in Berlin.
12 people died when a truck crashed into people, the driver is still being hunted.
Identity documents were found in the cab afterwards.
The country's president Joachim Gauck has reacted to the attack, after meeting survivors in a local hospital: "Shortly before Christmas we are obviously very much moved by the fate of the people.
"This is an attack against innocent people and this is an attack against our way of life."