Norwegian police have confirmed at least 10 deaths in a shooting at a youth camp in Norway, the NRK TV channel said.
A gunman dressed in a police uniform opened fire at random at the camp, hosted by the ruling Labor Party on the island of Utoya near Oslo, on Friday afternoon.
A witness earlier told the TV channel he had seen between "20 and 25" dead bodies at the camp, including several in the water.
Police have arrested the shooter. "We believe that he has had dealings with both events," national police chief Sveinung Sponheim was quoted by NRK as saying.
Witnesses reportedly described the attacker as looking "Norwegian."
The shooting came just hours after a massive bomb went off at the government headquarters in Oslo. At least seven people were killed and at least 19 were injured in the blast.
A suspected car bomb exploded near the office of Prime Minister Jens Stoltenberg. The premier is unharmed.
Police say the two attacks are linked. Observers have speculated that radical Islamist groups or terrorist organizations were behind the attacks.
UN Secreatery General Ban Ki-moon joined other world leaders in condemning the attacks. "The United Nations stands together with the people of Norway at this terrible moment," a statement issues by his spokesperson said.
