ISLAMABAD, Jan 14, 2006 (Reuters) – A Pakistani security official and residents of a border region said U.S. aircraft from Afghanistan killed 18 people, including women and children, when they fired missiles at pro-Taliban Islamists early on Friday.

Pakistani military spokesman Major-General Shaukat Sultan said up to 14 people had been killed in several blasts but he said he did not know the cause.

A U.S. military spokesman in Afghanistan , Lieutenant-Colonel Jerry O'Hara, said there were no reports of U.S. forces operating in the area.

The blasts in Pakistan 's Bajaur tribal region on the Afghan border came just days after Pakistan lodged a strong protest with U.S.-led forces in Afghanistan , saying cross-border firing in the nearby Waziristan area last weekend killed eight people.

Residents of Bajaur, opposite Afghanistan 's insurgent-troubled Kunar province, said the explosions were caused by firing from unidentified aircraft on the village of Damadola at about 3 a.m. (10:00 p.m. British time,Thursday).

The missiles destroyed houses of three tribesmen. Five women and five children were among 18 dead, while five people were hurt, journalist Anwar Ullah said after visiting the scene.

Those killed included 13 members of the family of one tribesman, Bakhpoor Khan, he said.

"It appears the Americans suspected some foreigners or wanted people were hiding in these houses. But there have never been foreigners in this area before."

A Pakistani intelligence official said four U.S. aircraft had intruded into Pakistani airspace and fired four missiles.

Another intelligence official said Damadola has been a stronghold of Tehrik-e-Nifaz-e-Shariat-e-Mohammadi (Movement for the Implementation of Mohammad's Sharia Law), a pro-Taliban group banned by Pakistan in January 2002.

He said members of the group might be involved in attacks on U.S.-led forces in Afghanistan and the missile strikes might have been launched in retaliation.

U.S. SAYS HAS NO INFORMATION

Damadola is close to the Afghan border, about 200 km (125 miles) northwest of the Pakistani capital, Islamabad .

Nearby Waziristan has been the scene of clashes between security forces and al Qaeda militants for more than two years, but there have been no previous reports of fighting in Bajaur.

On Monday, Pakistan lodged a protest with U.S.-led forces in Afghanistan , saying cross-border firing in the Mir Ali area of Waziristan the previous Saturday had killed eight people, including a woman, and wounded nine.

Residents in the area said they believed a helicopter gunship had attacked the house of a religious scholar who supports Afghanistan 's Taliban guerrillas.

Pakistan 's Foreign Ministry said U.S. authorities had denied their troops were involved in the Waziristan incident. It said it was not known if U.S.-led troops had been behind the firing but they were responsible for the Afghan side of the border.

U.S. forces have been in Afghanistan since 2001 pursuing the Taliban and their al Qaeda allies, including Osama bin Laden, mastermind of the September 11 attacks on U.S. cities.

U.S. officials have long said they believe bin Laden has been hiding on the rugged Afghan-Pakistan border.

In separate violence, suspected separatists in the troubled southwestern province of Baluchistan fired up to 10 rockets into an army camp east of the provincial capital, Quetta , late on Thursday, killing three soldiers, a provincial official said.

Baluch militants have been waging a low-level insurgency for decades seeking greater control of natural resources, but they have intensified their campaign in recent months.

(Additional reporting by Sayed Salahuddin in KABUL )