A Pashtun man uses a metal detector to sort through debris outside the Pearl Continental Hotel in Peshawar early morning on June 10, 2009, hours after a truck bomb exploded in it's parking lot. [Agencies] 

PESHAWAR, Pakistan -- Suicide attackers shot their way past guards and set off a massive blast outside a luxury hotel where foreigners and well-to-do Pakistanis mixed, killing at least 11 people and wounding 70, officials said.

The bombers struck the Pearl Continental Hotel late Tuesday at about 10 pm, when nightlife was still in swing. The attack reduced a section of the hotel to concrete rubble and twisted steel and left a huge crater in a parking lot.

The blast came a week after Taliban leaders warned they would carry out major attacks in large cities in retaliation for an army offensive to reclaim the nearby Swat Valley region from the militants. No claim surfaced immediately for the bombing in Peshawar, the northwest's largest city with about 2.2 million people.

Neither operation was anywhere near the size of the military's offensive in the Swat Valley, where 15,000 troops have battled up to 7,000 Taliban fighters.

But the battles Monday and Tuesday in the Upper Dir and Bannu districts suggest that pockets of pro-Taliban sentiment remain strong in some areas, while the militants' form of hardline Islam is unpalatable in others, particularly because of the violence the militants have used to enforce it.

Peshawar lies in between the two districts. The Pearl Continental, affectionately called the "PC" by Pakistanis, overlooks a golf course and a historic fort. The ritziest hotel in the city, it is relatively well-guarded and set far back from the main road.

Police official Liaqat Ali said witnesses gave vivid accounts of how the bombers carried out their attack.

Three men in a pickup truck approached the hotel's main gate, opened fire at security guards, drove inside and detonated the bomb close to the building, Ali said. A senior police officer, Shafqatullah Malik, estimated it contained more than half a ton of explosives.

The chaotic scene echoed a bombing last year at Islamabad's Marriott Hotel that killed more than 50 people. Both hotels were favored places for foreigners and elite Pakistanis to stay and socialize, making them high-profile targets for militants despite tight security.

The method of attack also matched a May 27 assault on buildings belonging to police and a regional headquarters of Pakistan's top intelligence agency in the eastern city of Lahore, for which the Taliban claimed responsibility. A small group opened fire on security guards to get through a guard post, then detonated an explosive-laden van.

In Washington, two senior US officials said the State Department had been in negotiations with the hotel's owners to either purchase or sign a long-term lease to the facility to house a new American consulate in Peshawar. The officials said they were not aware of any sign that US interest in the compound had played a role in its being targeted.

The officials spoke on condition of anonymity because the negotiations were not public and had not been completed. They said no immediate decision had been made on whether to go ahead with plans to base the consulate on the hotel grounds.

Lou Fintor, spokesman for the US Embassy in Islamabad, said there were no immediate reports of American casualties.