© Hakon Mosvold Larsen/EPA
Police with dogs patrol the centre of Kongsberg, Norway, after the attack on Wednesday night.
Several people have been killed and more injured in the Norwegian town of Kongsberg by a man armed with a bow and arrow, local police have said, adding that the attacker had been arrested and appeared to have acted alone.

"We can unfortunately confirm that there are several injured and also unfortunately several killed in this episode," Øyvind Aas, the police chief in the town, about 80km west of the capital, Oslo, told a press conference on Tuesday night.

Aas said the man had been detained and "according to our information, is the only person implicated". He declined to comment on the number of casualties but said the attacks happened over "a large area" and involved multiple crime scenes.

The attacker's motive was not yet clear, Aas said. The suspect had been taken to a police station in the nearby town of Drammen and no one else was being sought. Norway's minister of justice, Monica Maeland, was monitoring the situation.

The Norwegian public broadcaster, NRK, said police in Kongsberg, a municipality of about 28,000 people, received reports at about 6.15pm local time that a man was moving around the town centre firing a bow and arrow.

A "large number" of police, as well as helicopters, dogs and armed response teams secured the area soon afterwards, officials said. The shooting appears to have started in or near a Coop store in the city centre, they said, but details "are still confused".

A Coop spokesperson, Harald Kristiansen, told NRK there had been "a serious incident in our store" but none of its employees had been injured. "We are providing assistance to our colleagues and helping police with their investigation," he said.

"A lot of resources were sent from several places, including Oslo police district, the bomb squad, national police and emergency response teams," Aas told journalists. "They are securing the various crime scenes. We have many witnesses to interview."