Islamabad: Pakistan's parliament on Thursday denounced a ground assault inside its border territory by US-led coalition forces based in Afghanistan as an aggression against the country's sovereignty.

The pre-dawn attack on Wednesday on a village near the border reportedly killed 20 people, mostly women and children. The foreign troops arrived in the area on two helicopters and flew back after the raid.

The two houses of Pakistan's parliament adopted identical strong-worded resolutions against the first cross-border ground operation by the coalition troops.

In reaction to the attack, members of the National Assembly from tribal areas threatened to withdraw support to ruling coalition candidate for president Asif Ali Zardari in tomorrow's presidential election.

Political leaders, parliamentarians and civil society groups denounced the raid that has spurred widespread anger among people, particularly in the North West Frontier Province.

Foreign Minister Shah Mahmood Qureshi, speaking in the parliament, said the attack in the Angoor Adda area was "shameful, regrettable and unforgivable incident". He said Pakistan's sovereignty and territory was violated.

Qureshi said the attack was also violation of international norms and principles of UN charter.

The minister said the government had already lodged a strong protest with the US by summoning its ambassador to the Foreign Office. He said only innocent people including women and children died in the attack and there has been no reports of any high value target being hit.

"Pakistan is committed to fight against extremism and terrorism and our track record proves that Pakistan Army has laid down their lives to fight this monster," he said.

Four islamists killed

Four Islamist militants were killed and five wounded in a missile attack by a suspected US drone in Pakistan's North Waziristan tribal region on Thursday, security officials and witnesses said.

The attack targetted the house of a tribesman, Rehman Wali, in the Mohammad Khel area, near the border with Afghanistan, where the militants were hiding.

"Apparently three missiles were fired by the drone," a witness in the area said on condition of anonymity.