Sky News 
Friday, July 22, 2011
Update: Four people killed during shooting at ruling Labour party youth meeting on Utoya Island, Norway
Norwegian police have said that an explosion in Oslo this afternoon was caused by a bomb, and has led to “deaths and injuries” – while there are reports that shots have been fired at a nearby children’s camp.
There are reports that some shots were fired at a youth meeting near the capital.
As many as 700 people were believed to be taking part in the summer camp.
Police have told people in the Norwegian capital to stay away from the city centre and limit the use of mobile phones.
They also warned people to avoid large gatherings.
Full story here. 
Neil Perry has sent me more details of the shooting on the Labour party youth camp, which suggests co-ordinated attacks. It is a Google translation from Dagbladet , tidied up a bit, so it is not perfect.
Eyewitnesses told the AP that a man dressed as a police officer has fired several shots at Utøya in Buskerud. AP spoke with one of those who were on Utoya where there is an AUF event with over 700 people.
“Suddenly, we heard lots of shooting. People had to run and hide. We have been told to get off the island.”
“We now have reports of a serious situation there – a critical situation on Utøya,” Prime Minister Jens Stoltenberg told TV 2
The police are now on site and sealed off the area. Bjorn Jarle Røberg-Larsen of Labor, is not in Utoya, but has had telephone contact with young people who are on the island.
“They say that at least one person wearing a police-like uniform was firing shots with a handgun,” he said.
He says that the young people he talked to were hiding and dared not speak on the phone anymore for fear of being discovered by the perpetrator.
“Young people have to swim in panic, and it is far to the mainland from Utoya. Others are hiding. Those I spoke with did not want to talk more. They were terrified,” he said to VG Nett.