British newspapers reported Friday at least 55 people were killed and about 700 more injured in Thursday's attack on London's bus and subway system.
On Friday, local police said 13 people were killed in the double-decker bus attack in central London. Earlier, officials said they were unable to provide an accurate death toll for the bus bombing.
Earlier, Police Commissioner Sir Ian Blair confirmed the death toll currently stands at above 50. Dozens of people are still hospitalized in serious condition in the wake of the attack.
Another police official said each of the four explosive charged detonated in Thursday’s attack weighed 10 pounds (about 4.5 kilos) or less.
Meanwhile, London residents are attempting to return to a normal routine. Subway traffic in the British capital was resumed and most lines, as well as city buses, are operating as usual.
Police investigators are currently looking into the modus operandi adopted by the terrorists behind the attack. Officials have not yet ruled out the possibility of suicide bombers but are also looking into the possibility of bombs detonated by timers or cellular phones.
British Home Secretary Charles Clarke confirmed the police are still considering the possibility of suicide attacks and warned that terrorists could strike the capital again. He added that Britain was taking the al-Qaeda claim of responsibility seriously.
Meanwhile, a senior Pentagon official said the claim of responsibility is apparently credible, as it was published on an Islamic website that has accurately reported on attacks against American forces in Iraq and Afghanistan.
Map of the blasts
Read Ynetnews' full coverage of Thursday's al-Qaeda attack in London
- Analysis: war declared on Britain
- Center of hatred
- Reliving the trauma
- 'London under attack'
- London Jews on high alert
Earlier, British Foreign Secretary Jack Straw said the attack bore the hallmarks of an al-Qaeda strike, and an unknown al-Qaeda-affiliate in Europe said it carried out the attack on the "crusading Zionist nation of Britain" in revenge for the wars in Iraq and Afghanistan.
"In response to the massacres carried out by Britain in Iraq and Afghanistan our heroic warriors have carried out a blessed raid in London. Britain is now burning with fear, terror and fright from the north to the south, east and west. We have warned the British government and people again and again," said the group on an Islamist website.
The group also warned Denmark, Italy "and all the Crusader governments" to pull out of Iraq and Afghanistan or face similar attacks.
However, in a televised news conference, Deputy Assistant Commissioner Brian Paddick said that he was not sure about the authenticity of the internet announcement.
One Israeli woman, Hagit Kleiman, 38, said she never thought terrorism would follow her all the way to London.
'We were on the way to tour some of the galleries in town when we got caught in the attack," she told Ynet. "We never heard the blast, but my friends in the area told me there were a ton of ambulances and fire engines.
"They were obviously very ready for this. It was like they'd been waiting for it."
- Israelis in London are welcome to give their personal accounts of terror attack on Ynet's forum page
- Israelis and Jewish Londoners - send us your eyewitness accounts and thoughts
World condemns, Olympics to go on
The U.N. Security Council unanimously condemned attack, and the International Olympic Committee said it would not rethink its decision to grant the 2012 Olympics to London, saying it had "complete faith" in Britain's ability to host the games and provide security for the athletes.
Pope Benedict XVI said he deplored the "terrorist attacks" in London, calling them "barbaric acts against humanity," and said he was praying for the families of the victims.
French Prime Minister Dominique de Villepin described the attack as "odious," and expressed "profound solidarity, friendship and support for the British people.
Andrew Friedman, Attila Somfalvi, Modi Krietman, Ronny Gal and Orly Popper of Ynet and Ynetnews, and Leslie Bunder of Something Jewish contributed to this report