A survivor of the attack at a Norwegian youth camp has told how he was "terrified" as he hid behind rocks and saw others being shot.
Jorgen Benone said the group had just finished talking about what had happened in Oslo before sitting down to eat.
He said suddenly, they were aware of "panic" down by the water.
"People were wondering, what's happening?... Then people began understanding that people had been shot," he said.
"People started jumping out of windows, running everywhere, all directions - they were terrified for their life.
"Most people ran towards the water, hiding behind stones... They guy was dressed like a policeman.
"It was total chaos, people were jumping into the water trying to swim to the other side.
"I think several lost their lives that tried to get over to the mainland.
"People were hiding behind stones. Some were just sitting, all quiet. I saw people being shot.
"I tried to sit as quiet as possible behind a stone. I felt it was best not to move anywhere... not to run in the open because then he could see me.
"I saw him once - just 20-30 metres away from me. I thought, I'm terrified for my life.
"I thought about all the people I love and I just wanted to go home.
"I saw some boats, but I wasn't sure if I could trust them. I didn't know who I could trust anymore.
"But then I started waving and a boat came towards me and I just jumped into the water and swam to the boat, and I was crying, that's how happy I was.
"I'm just happy to be alive."
Another survivor of the attack told Sky News how dozens of children fled screaming after the gunman opened fire.
Emilie Bersaas, 19, said: "I saw a lot of people running and screaming so I ran to the nearest building and hid under a bed.
"The shooting came from all different directions.
"It was very terrifying. At one point the shooting was very, very close to the building - I think it actually hit the building one time.
"The people in the next room screamed really loud.
"We're all a bit shaken up right now because we don't know who is fine and who is not fine.
"I'm a little worried about my friends and the other people on the island.
"I know that some are fine but there are a lot of people I know nothing about."
An eyewitness has reported seeing as many as 30 bodies on Utoya - the island hosting a youth meeting of the ruling Labour Party.
Around 600 people were believed to be taking part in the summer camp - most of whom were teenagers aged between 14 and 18.
The attack happened shortly after a bomb exploded near government buildings in Oslo.