Britain is taking "extremely seriously" claims by the man believed responsible for killing more than 70 people in Norway that he had links with far-right groups in England, Prime Minister David Cameron says.
Mr Cameron said that Britain shared "the sorrow and the anger" felt in Norway over the killings and would offer any support that Oslo needs in the wake of the massacre.
Norwegian authorities on Monday revised down from 93 to 76 the total number of fatalities from Friday's bomb-blast in Oslo city centre and shootings at Utoya Island, though it remains one of the worst mass murders of modern times.
Police said that the death toll at the Labour Party youth camp on Utoya was being reduced from 86 to 68 after overcounting caused by the fact that police and rescuers were focusing on helping survivors. Meanwhile, the number killed by the bomb blast outside government headquarters in Oslo rose from seven to eight.
The man accused of the killings, Anders Behring Breivik, has confessed carrying out the attacks, but denied criminal responsibility. He today entered a not guilty plea at a closed hearing in an Oslo court.
Judge Kim Heger later said that Breivik had told him that he wanted to save Europe from a Muslim takeover and claimed that two further cells existed in his organisation. He said his bombing and shooting rampage was intended to send a "strong signal to the people" and deter future recruitment to the Labour Party, which he blamed for allowing "mass imports of Muslims", said the judge.
Breivik was remanded in solitary confinement for eight weeks.
Prosecutor Christian Hatlo said that the 32-year-old told investigators during his interrogation that he never expected to be released from jail.
In a rambling 1,500-page manifesto posted online shortly before the attacks, Breivik said that he was acting alone but had been recruited to the radical cause by two English right-wing extremists at a meeting in the UK in 2002.
The Prime Minister later visited the Norwegian Embassy in south west London, where he signed the book of condolence. He wrote: "Everyone in Britain stands with the people of Norway at this time of great sadness and mourning. We remember those who lost their lives in Oslo and Utoeya on 22nd July in an act of appalling barbarism. We know that the courage, the decency and the resilience of the Norwegian people will overcome this evil. David Cameron."
