Islamic extremists have been using Iraq (search) as a planning center for attacks around the world since losing Afghanistan as their base in 2001, the government's chief spokesman said Friday.

Speaking about Thursday's blasts in London (search) that killed more than 50 people, Laith Kubba said "we don't know exactly who carried out these acts but it is clear that these networks used to be in Afghanistan and now they work in Iraq."

The spokesman said that insurgents in Iraq and those who carried out the London attacks "are from the same network. There are different groups in the world, but they all follow the same school."

Kubba was referring to hardline Muslim extremists who label people who don't agree with them as infidels.

"We don't know exactly who enters Iraq then leaves to carry out attacks with explosives around the world," he told The Associated Press.

Iraq's government has accused Syria (search) of allowing insurgents to cross its porous border into Iraq — a claim Damascus denies, saying it cannot fully control its portion of the frontier.

Meanwhile, President Jalal Talabani condemned the London attacks because "these vile crimes reflect the moral bankruptcy of those who conducted them in the name of humanity."

"Terrorism has become an international plague that does not discriminate between races, people or religions," Talabani said in a letter to British Prime Minister Tony Blair.

Insurgent attacks in Iraq have killed thousands since the fall of Saddam Hussein's regime in April 2003. Britain has been the United States' closest ally in Iraq and has hundreds of troops in southern regions.