
A boy, 13, has been arrested after a ‘grenade’ exploded in Oslo, Norway.
The deafening blast went off in the Bislett neighbourhood at 8.43pm on Tuesday.
No injuries were reported at the scene, near the OsloMet university campus, according to Norway’s Aftenposten.
The blast is believed to have been caused by a hand grenade, operations manager Øyvind Hammervold said.
Police then detonated a second unexploded, ‘military-style’ hand grenade at around 9.44pm.
More explosive devices still being in the area has not been ruled out.

One minor has been arrested, but there could be more people involved, incident commander Brian Skotnes said.
Witnesses reported drones flying over the area as residents were told to stay away from windows.
Tina Sviggum, 25, said she and her flatmate in Pilestredet heard a ‘a bang, a real boom’. Running to their window, she told VG they saw a man running.
‘He waved his arms and shouted that there was a grenade in the way,’ Tina added.
‘A car wanted to drive on, but then the man stood in front and stopped the car again. He wasn’t panicking, more like someone who took control and responsibility.’
A driver said the ‘violent bang’ blast damaged his car as he was driving through the area.

‘The entire side is damaged and the windows on one side are broken,’ he said, sharing a photograph of the shattered window.
‘Everyone heard it, and people started running.’
Another bystander told NRK: ‘The explosion was so loud that our ears hurt.’
The first blast reportedly also triggered emergency alerts to ring on several mobile phones.
Photographs from the scene show an unexploded hand grenade can be seen in the middle of a pedestrian crossing.
A boy arrested by police was reportedly born in 2012, with police saying the explosions were down to a ‘showdown between criminals’.
Incident commander Brian Skotnes said: ‘We have a certain overview, but we are working hard to get a broader picture.’
He added that police believe several people were involved in the explosion.
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