US Secretary of State Hillary Clinton regretted the death of Salman Taseer, governor of Punjab province, saying he had promoted tolerance.

UN Secretary General Ban Ki-moon called his death "a loss for Pakistan".

UK Foreign Secretary William Hague said he was "shocked" by the killing.

Pakistan's high commissioner to London, Wajid Shamshul Hassan said that the assassination exposed the divisions in his country.

"It has shown that you can be held hostage by a minority of religious people and they can do whatever they want. That is not the way we are going to allow in the country," he said.

Mr Taseer was shot dead by one of his bodyguards angered over the governor's opposition to blasphemy laws.

Witnesses said he was riddled with bullets from an automatic rifle as he returned to his car at the Kohsar Market, a shopping centre in Islamabad.

Prime Minister Yousuf Raza Gilani declared three days of national mourning and appealed for calm. He also ordered an immediate inquiry into Mr Taseer's killing.

Mr Taseer's body has been taken to Punjab's capital, Lahore, where a state funeral will be held.