Youth known to intelligence agencies incarcerated on mistrust of managing explosives, Norways security service says

A 17 -year-old has been arrested in connection with an explosive machine found near a busy subway station in Oslo and defused before it explosion, Norways security service has said.

Signe Aaling, chief prosecutor with the PST security service, said on Sunday that the youth had been detained on mistrust of managing explosives.

The security service head, Benedicte Bjornland, said it was unclear if the teen had plans to carry out an attack with the homemade device.

The youth was not recognized but Bjornland said intelligence agencies had been aware of him. He was an asylum seeker from Russia who arrived in Norway in 2010.

Norwegian police carried out a controlled explosion of the bomb-like machine in central Oslo on Sunday. Media at the scene described a loud bang shortly after the bomb squad arrived with a remote-controlled robot. The field had been cordoned off on Saturday night.

The noise from the blast was louder than our explosives themselves would make, a police spokesman mentioned, adding that further investigation was needed to find out if the machine had contained explosives.

The device, measuring about 1ft( 30 cm) across, appeared to be capable of making merely a limited amount of damage. Forensic experts will examine fragments to figure out what it was.

Police have been on heightened alert since a truck ploughed into a crowd in Stockholm on Friday. Four people were killed and 15 were injured during what police called an apparent terrorist attack.

Read more: https :// www.theguardian.com/ world/ 2017/ apr/ 10/ teenage-russian-asylum-seeker-arrested-over-explosive-device-in-oslo