Afghan officials say at least nine people were killed Friday in twin suicide bombings and a gun battle at a British cultural center in Kabul.

Shots were still heard hours after the suicide bombers started the attack. Several more explosions were heard inside the British Council compound.

The Taliban has claimed responsibility for the attack, which took place as Afghanistan celebrated the country's 1919 independence from Britain.

On Thursday, a roadside bomb killed 21 people travelling in a minibus in western Afghanistan's Herat province.

Afghan President Hamid Karzai and NATO condemned that attack, which was also blamed on Taliban insurgents.

Violence in Afghanistan is at its worst since the U.S.-led invasion in late 2001, with international troop and Afghan civilian deaths reaching record levels.