Six persons, including three women, were killed and 20 others injured in a missile strike by unmanned US drones on a house and a seminary linked to a key Taliban commander Jalauddin Haqqani in Pakistan's restive North Waziristan tribal region on Monday.

The suspected drones operated by the US-led forces in Afghanistan fired six to seven guided missiles at the seminary in Tanda Darpakhel, two kilometres from Miranshah, the headquarters of North Waziristan.

Four missiles hit a madrassa run by senior Taliban leader Jalaluddin Haqqani while three hit nearby houses. A news agency quoted official sources and local residents as saying.
Three female seminary students and three labourers were among the dead, official sources said, but other sources said that among the killed were three militants.

Whether Haqqani, who is a close aide of fugitive Taliban leader Mullah Omar was present in the area or not at the time of the strike, was not known.

The Pasthun leader of Khost in Afghanistan has not seen since the fall of the Taliban regime in Kabul in 2001.

Taliban fighters surrounded the area around the madrassa and did not allow people to approach the site. North and South Waziristan tribal regions are considered strongholds of the Pakistani Taliban led by Baitullah Mehsud.

Since last week, Pakistan's tribal belt has witnessed a sharp increase in attacks by drones operated by US-led coalition forces in Afghanistan. More than 40 people have died in these attacks.

Twenty people, a majority of them women and children, were killed in a raid in South Waziristan by gunship helicopters and commandos of the coalition forces on September three.

That attack marked the first time that US-led ground forces from Afghanistan had intruded into Pakistan.