Experts believe the explosions in London were carried by al-Qaida. Attacks on crowded trains and other hard-to-guard public spots, an effort to seed maximum chaos and a quick claim of responsibility – these are the distinguishing features of al-Qaida terrorist activity. A series of terrible explosions in London are likely to be followed with other acts of terrorism, Sergei Goncharov, a spokesman for the Russian rescue group Alpha said. The expert believes that it is important for terrorists to attract global attention to their activities. "The fact of G8 summit taking place in Great Britain and London's yesterday victory in the Olympic Games voting pushed al-Qaeda terrorists to organize a series of terrorist attacks in London and remind the whole world of their existence," Sergei Goncharov said.
In the London attacks, which killed at least 40 people and wounded hundreds, there was no immediate sign that suicide attackers set off the blasts, reports the AP.
"This one is very similar to the attack in Madrid: a soft target, full of people, coordinated attacks, at rush hour. All are indications of al-Qaida," said Diaa Rashwan, a Cairo-based expert on militants.
But the London bombings may have even greater significance, he believes, because of the British capital's international status and because of the timing. The blasts on three underground trains and a double-decker bus came as leaders of the Group of Eight, the world's most powerful nations, were meeting in Scotland.
"There is ... a very high alert for the G8 summit. For such an attack to take place despite all of that is undisputable proof of the failure of American and British security policies," said Rashwan, an expert at the Al-Ahram Center for Strategic Studies.
The bombings certainly do underline the difficulty of defending public facilities in Europe, said Magnus Ranstorp, a terror expert at St. Andrews University in Scotland.
London and its transportation network are "a very tempting target; it's one of the most obvious targets in Europe," he said. "It's impossible to guard against this."
A single group, al-Qaida in Europe, claimed both the Madrid and London bombings. But that may just be a name covering a number of cells working in coordination, some experts believe.
Ten to 20 people in several loosely affiliated group were likely involved in the London attacks - because mounting such synchronized attacks "requires major coordination," Ranstorp said.
Mohammed Salah, an expert on Islamic radicals and the Cairo bureau chief of the Arab newspaper Al-Hayat, said the operation may have been carried out by a "sleeper cell" overlooked by Britith security - "something similar to the Hamburg cell lead by Mohammed Atta," one of the Sept. 11 suicide hijackers who had been based in Germany.
Osama bin Laden and his deputy in al-Qaida, Ayman al-Zawahri, have threatened Britain along with other countries in their recent messages, he noted.
"It proves that they still exist and at a large scale despite the war against terrorism," he said of the London bombings.
On Thursday, a statement on an Islamic Web site signed by the group's "secret organization" said Thursday's bombings were a "response to the massacres Britain committed in Iraq and Afghanistan."
It also warned Denmark and Italy the would "receive the same punishment if they do not withdraw their troops from Iraq and Afghanistan."