Sappers successfully dismantled a bomb discovered Thursday next to a confessional inside Madrid's La Almudena Cathedral, Spanish police said.

The device contained 200 grams of gunpowder, a small cylinder of butane, a kilo (2.2 pounds) of metal screws and a alarm-equipped watch, they said.

A priest found the bomb inside a bag that he noticed while exiting the confessional. He quickly cleared the cathedral of worshippers and tourists and contacted authorities, police sources told Efe.

Members of the police bomb unit, Tedax, defused the device without incident.

Investigators suspect the bomb may have been planted by an anarchist group or a mentally disturbed individual, the police sources said.

Police kept the cathedral cordoned off for several hours. EFE