DERA ISMAIL KHAN, Pakistan — Suspected U.S. missiles killed 20 people at the house of a Taliban commander near the Afghan border today, the latest volley in a two-month onslaught on militant bases inside Pakistan, officials said.

Missile attacks have killed at least two senior al-Qaida commanders in Pakistan's wild border zone this year, putting some pressure on extremist groups accused of planning attacks in Afghanistan — and perhaps terror strikes in the West.

However, a marked uptick in their frequency has badly strained America's seven-year alliance with Pakistan, where rising violence is exacerbating economic problems gnawing at the nuclear-armed Islamic republic's stability.

The reported missile strike occurred in South Waziristan, part of a belt of tribally governed territory considered a possible hiding place for Osama bin Laden and al-Qaida No. 2 Ayman al-Zawahri.

Two intelligence officials, speaking on condition of anonymity because they are not authorized to speak to media on the record, said the targeted house in Mandata Raghzai village belonged to a lieutenant of local Taliban chief Maulvi Nazir.

The officials cited reports from agents and informers in the area. They said the identity of as many as 20 bodies pulled from the rubble was not immediately clear.

Mohammad Noor Wazir a resident of a nearby village, said he watched from a distance as militants surrounded the scene and loaded at least 15 corpses into vehicles that drove away.

Three other victims were buried in the village cemetery, including a brother of the owner of the destroyed house, Wazir told The Associated Press by telephone.

American commanders complain that Pakistani forces have not put enough pressure on militant strongholds on their territory.

In a reflection of that frustration, U.S. military and CIA drones that patrol the frontier region are believed to have carried out at least 15 strikes since mid-August. The United States rarely confirms or denies involvement.

Pakistan's new leaders have protested the missile strikes — as well as a highly unusual raid by helicopter-borne commandos in September — as unacceptable violations of their sovereignty.

In a resolution adopted Monday, Pakistani senators condemned the U.S. drone attacks, saying they caused "immense" loss of life and were undermining Pakistan's efforts to defuse militancy through dialogue.

The government should take "more effective measures" to stop such attacks, it said, without recommending any specific action beyond official protests to Washington and NATO.

In other violence on Monday, a car bomb exploded in a parking lot in the frontier city of Quetta, killing a rickshaw driver and another unidentified person and injuring 10 others, while the army said it killed 10 militants in the troubled Swat valley.

Pakistan's military is involved in heavy fighting with militants in the Bajur region as well as in Swat. It claims to have killed 1,500 insurgents in a two-month offensive in Bajur that has drawn U.S. praise.

Yet many Pakistani are weary of a war they believe is being fought at America's behest and the government has offered to negotiate with any militant group willing to renounced violence.

"There is an increasing realization that the use of force alone cannot yield the desired results," Pakistani Foreign Minister Shah Mehmood Qureshi told a gathering of Pakistani and Afghan tribal elders.

The meeting in Islamabad was part of a dialogue process begun last year in hopes that it could ease often strained relations between Pakistan and Afghanistan.

Afghan President Hamid Karzai has repeatedly accused Pakistan, which backed the Taliban takeover of Afghanistan prior to the Sept. 11, 2001 attacks on America, of secretly continuing to aid the militants as a way to exert influence over its poorer neighbor.

Pakistan denies the charge. However, it has also seized on recent indications that Afghanistan's government is also seeking talks with the Taliban to press for compromise.