DERA ISMAIL KHAN, Pakistan - A suspected U.S. missile strike inside Pakistan on a compound used by Taliban militants near the Afghan border killed up to 20 people early Monday, Pakistani officials said.

U.S. missile strikes into Pakistan's border region have escalated sharply in recent months in the search for militants, despite protests from the Pakistani government.

Two Pakistani intelligence officers, speaking on condition of anonymity because they were not authorized to talk to the media, said Monday's strike occurred the South Waziristan region.

The targeted house was frequented by followers of a Taliban commander, but that the identity of the victims is not immediately clear, the officials said.

Meanwhile, Taliban fighters who tried unsuccessfully to kidnap a tribal militia leader beheaded one of the man's rescuers in front of a crowd, then fought a running battle with tribesmen on Sunday that left as many as 30 people dead, police said.

The assailants grabbed militia chief Pir Samiullah at his home in the Swat region and were hustling him to a getaway car when dozens of local tribesmen confronted them and snatched him back, regional police chief Dilawar Bangash said.

Bangash said hundreds of Taliban later returned, seized three members of the militia and beheaded one of them on a road before a large crowd.

The militias, known as lashkars, have been compared to the so-called awakening councils that have helped U.S. forces turn the tables against al-Qaida in Iraq. Pakistan's government has cited them as proof it can root out militants waging an insurgency in both Pakistan and Afghanistan.

At the beheading, Taliban commander Mullah Shamsher told onlookers "this was a lesson for anyone who tried to oppose them," Bangash said, citing witnesses. The militia gathered men from the surrounding area who engaged the Taliban in an hours-long gunbattle.

Bangash said 20 militants including Shamsher, six militiamen and four bystanders were killed and another police official said several tribesmen were reported missing.

Muslim Khan, a militant spokesman contacted by telephone, confirmed a clash but said only three Taliban died. He claimed 12 tribesmen were killed and 62 were abducted.

"Our tribal brothers, those who are patriots, have broken with them (the militants), and lashkars are fighting against those involved in terrorism," Pakistani Prime Minister Yousuf Raza Gilani said Sunday.

Yet many doubt the ramshackle forces can face down heavily armed insurgents who have seized swaths of Pakistan's border belt, forged ties with al-Qaida, and targeted pro-government elders with suicide bombings and kidnappings.

Officials deny they are arming the militias, though observers suspect that they at least receive government funding.

Insecurity and government restrictions make it virtually impossible to verify accounts of the fighting raging mainly in Swat and nearby regions on the Afghan border.