A pro-Taliban group in Pakistan has claimed responsibility for an attack on a UN compound in the Pakistani capital of Islamabad.

Spokesman for Tehreek-e-Taliban (TTP), Azam Tariq, said it had conducted Monday's bomb attack on the World Food Program's Pakistan headquarters that killed five people, the Associated Press reported on Tuesday.

Tariq accused the center of promoting the American pursuits in Pakistan. He also blamed the UN for remaining silent on 'the killings' in northwestern tribal areas bordering Afghanistan, which continuously come under missile attacks by US drones.

Senior city police official, Bin Yameen, earlier claimed that the discovery of a blown off head and two legs near the heavily-fortified building suggested that the bombing had been a suicide raid.

UN Secretary General Ban Ki-moon has condemned the attack as a 'heinous crime.' The world body has also temporarily shut down all its offices in Pakistan while investigations are underway.

The developments came as the US, which has not been successful in arresting or eliminating any key militant leaders in the neighboring Afghanistan, despite an eight-year military presence there, considers to expand its military campaign to Pakistan, where, Washington claims, most militant chieftains have fled to.

Based on the claim, the current US administration has almost doubled the number of its missile attacks on the alleged 'militant hideouts' across the Pakistani border with Afghanistan. Only one-sixth of such raids have so far managed to actually hit pro-Taliban hideouts, according to the Pakistani media, prompting Islamabad to step up its objection to the US air strikes.

Tens of thousands of Pakistanis poured into streets in several cities last week to protest US bombings and intervention in their country, expressing their disgust by “Death to America” slogans.

HN/MB