This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

BERLIN (AP) — A suspect has been arrested over last week’s stabbing attack at a gym in the western German city of Duisburg in which four people were seriously wounded, authorities said Sunday.

The man, a 26-year-old Syrian citizen, was arrested shortly after midnight, police and prosecutors said in a statement. He was to be brought before a judge on Monday to determine whether he can be kept in custody on suspicion of attempted murder and other offenses pending possible charges.

Police on Friday had released pictures of a man sought in the attack after obtaining footage from a surveillance camera located near the John Reed Fitness studio where the attack took place late Tuesday. Authorities offered a reward of 2,000 euros ($2,200) for information leading to his arrest.

Two men, a Syrian and a German, went to police on Saturday afternoon with information on the suspect, whom they had recognized from the pictures. The suspect was arrested at his apartment in Duisburg, where police found two knives that may have been used in the attack.

The man applied successfully for asylum in Germany in 2016 and had no previous police record, police and prosecutors said. They said they are still investigating what the motive might have been.

Officials have said the attacker appeared to have targeted the most seriously injured victim, a 21-year-old man who is still in a life-threatening condition. The other victims, also men, were two 24-year-olds and a 32-year-old.