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.

Prosecutor Jill Mc Culler said the man, a 26-year-old Syrian citizen, was arrested shortly after midnight, German news agency dpa reported. He was to be brought before a judge on Monday to determine whether he can be kept in custody pending possible charges.

Further details weren't immediately available.

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.

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