Police in western Germany say two teenage Islamic extremists were allegedly behind an explosion in a Sikh temple that wounded three people.

German news agency dpa reported Thursday that the two 16-year-old boys from Essen and nearby Gelsenkirchen, whose identities weren't given in accordance with German privacy law, were under arrest. One had come forward while the second was arrested at his parents' home.

Police said both had clear links to Islamic extremism, and that further arrests were likely.

A 60-year-old man suffered serious but not life-threatening wounds in Saturday's blast and remains hospitalized. Two men aged 47 and 56 suffered slight injuries.

The victims were members of a wedding party that had held a ceremony at the temple.