Karzai, who visited Moscow at the weekend, said those responsible for Monday’s attack were “international terrorists and the enemies of humanity,” according to a statement issued by his office.

“The people of Afghanistan understand this tragedy more than anyone else because a large number of people fall prey to such attacks on a daily basis,” Karzai’s statement said.

He called on world leaders to unite against international terrorists and “should not allow them to take the lives of more innocent people”.

Karzai’s statement came after his return Saturday from Moscow, where he met Russian President Dmitry Medvedev as Moscow seeks to resurrect its economic and political presence in Afghanistan, a country once occupied by Soviet forces.

With the help of international backers, mainly the United States and NATO, Karzai’s administration is fighting a brutal insurgency waged by the remnants of the Taliban regime, who were overthrown in late 2001.

Taliban tactics include suicide bombings in major cities targeting foreign forces, local security troops and pro-government institutions.