KARACHI - Pakistan's Taliban on Wednesday claimed responsibility for a suicide bombing that killed 43 people in the commercial capital Karachi, and threatened more attacks on the U.S. ally.
My group claims responsibility for the Karachi attack and we will carry out more such attacks, within 10 days, said Asmatullah Shaheen, one of the commanders of Tehrik-e-Taliban Pakistan (TTP), or Taliban Movement of Pakistan, who spoke by telephone to a Reuters reporter in Peshawar.
The prospect of more violence comes at a tricky time for Pakistani President Asif Ali Zardari, who already faces political heat because corruption charges against some of his aides may be revived.
And Zardari has yet to formulate a more effective strategy against the Pakistani Taliban, despite relentless pressure from Washington, which wants his government to root out militants who cross over to attack U.S. and NATO-led forces in Afghanistan and then return to their Pakistan strongholds.
The scale of his troubles were clear on Monday, when a suicide bomber defied heavy security around a Shi'ite procession in Karachi, killing 43 people and triggering riots.
In a sign of mounting frustrations, Karachi religious and political leaders called for a strike for Friday to condemn that attack, one of the worst in the city since 2007.
The bloodshed illustrated how the Taliban, whose strongholds are in the tribal, lawless northwest, have extended their reach to major cities in their drive to topple the government.
More than a dozen factions based in different parts of northwest Pakistan formed the TTP, or Taliban Movement of Pakistan, a loose umbrella group, in late 2007.
Taliban bombings have killed hundreds of people since October, despite a major army offensive against them, and attacks by pilotless U.S. drone aircraft.
Shaheen heads one of the group in the TTP. The government has put a 10 million rupees ($120,000) price on his head.
The Taliban have infuriated many Pakistanis with public hangings and whippings of those who disobey their hardline brand of Islam.
But Zardari's ties with Washington are also deeply unpopular. The Karachi bomb suggested growing violence has raised suspicions of Pakistan's government.
The organised way that all this is being done clearly shows that the terrorists are being sponsored either by the government itself or some other state that wants to destabilise Pakistan, said Noman Ahmed, who works for a Karachi clearing agency.
Pakistan's all-powerful military sets security policy. So the key gauge of public confidence may be how the army's performance is viewed. In the 1980s, it nurtured militants who fought Soviet occupation troops in Afghanistan. Then the Taliban emerged in the 1990's after a civil war tore apart Afghanistan.
Now Pakistan's army faces brazen homegrown militants. If it does what Washington wants it to -- wipe out militants who operate in Afghanistan -- it may lose what is sees as vital leverage in Afghanistan when U.S. troops pull out.
I don't buy that foreign hands are involved (in the Karachi attack). They're domestic elements. They're those who were nurtured, trained and protected in late 1990s, said Sajid Ali Naqvi, head of the influential Shi'ites' Islami Tehrik movement.
The bombing was one of the bloodiest in Karachi since an October 2007 attack on former Prime Minister Benazir Bhutto on her return to the country that killed at least 139 people.
A murky network of Pakistani militants complicates the government's counter-insurgency efforts.
The fact that they (Taliban) have accepted responsibility doesn't really mean they would have done it, said Mehmood Shah, former security chief in Pakistan's tribal areas.
There are so many groups which are independent, yet when the Taliban come to know of such incidents, they take responsibility in order to take credit.
(For more Reuters coverage of Afghanistan and Pakistan, see: here
(Additional reporting by Kamran Haider, Augustine Anthony and Alamgir Bitani; Writing by Michael Georgy; Editing by Alex Richardson)