Khar: Pakistani aircraft bombed militant strongholds in a northwestern region on Tuesday while US drones prowled the sky over another militant sanctuary on the Afghan border, a military official and residents said.

Pakistani forces launched offensives against Al Qaida and Taliban militants in the northwest in August and the government says hundreds of militants have been killed.

But at the same time, US forces have stepped up strikes on militants on the Pakistani side of the border, angering Islamabad and straining relations between the allies.

Pakistani aircraft bombed three areas of Bajaur on Tuesday as ground troops searched house-to-house for militants, a military spokesman said.

"They have constructed underground bunkers and along with foreign fighters are putting up stiff resistance. Troops are clearing each and every house in these areas," said military spokesman Major Murad Khan.

Casualty toll unknown

Khan had no information about casualties in Tuesday's fighting but the military has said 117 have been killed in Bajaur over the past week.

An intelligence official in Bajaur said a helicopter gunship had killed nine militants in an attack on a vehicle east of Khar, the region's main town.

An intensifying insurgency in Afghanistan has put pressure on Pakistan to go after militants operating out of sanctuaries in remote enclaves on its side of the border, such as Bajaur.

Worry over Afghanistan's prospects has also led to stepped-up US strikes on militants in Pakistan.

Pakistan's new government has committed itself to the US-led campaign against militancy even though it is deeply unpopular.

But it objects to cross-border strikes and angrily protested against a bloody helicopter-borne ground assault by US commandos in South Waziristan early this month.

Pakistan says US strikes and the civilian casualties they inflict drive people into the arms of the militants.

The Pakistani army has said the country's territory would be defended at all costs but Prime Minister Yousuf Raza Gilani has said Pakistan aimed to settle the issue with the US diplomatically.

In talks with British Justice Secretary Jack Straw, Gilani called for an immediate halt to violations of Pakistan's territory, the prime minister's office said.

Pakistan's armed forces were fully capable of handling any situation by themselves, Gilani was quoted as telling Straw.

US-operated drones flew over the North Waziristan region on Monday night and yesterday morning but did not fire, residents said.

President Asif Ali Zardari, who is close to the US, was in Britain yesterday where he was due to meet Prime Minister Gordon Brown for talks expected to focus on security.

Zardari was elected president this month to replace staunch US ally Pervez Musharraf, a former army chief who stepped down as president last month under threat of impeachment.

New order: Stop US raids with force

Pakistan's military has ordered its forces to open fire if US troops launch another raid across the Afghan border, an army spokesman said on Tuesday.

The orders mark a dangerous escalation in tension between Washington and a key ally in its seven-year war on terrorism, less than two months before the US elects a new president.

Pakistani protests are growing in the wake of a September 3 incident in which helicopters ferried US commandos into Pakistan for a highly unusual ground attack on a militant stronghold.

The country's civilian leaders have stressed that Pakistan must resolve the dispute through diplomatic channels. However, army spokesman Major General Athar Abbas said that, after the cross-border assault in the South Waziristan tribal region, the military told its field commanders to take action to prevent any similar raids.

"The orders are clear," Abbas said in an interview. "In case it happens again in this form, that there is a very significant detection, which is very definite, no ambiguity, across the border, on ground or in the air: open fire."

US military commanders accuse Islamabad of doing too little to prevent the Taliban and other militant groups from recruiting, training and resupplying in Pakistan's wild tribal belt.

Pakistan acknowledges the presence of Al Qaida fugitives and its difficulties in preventing militants from seeping through the mountainous border into Afghanistan.

However, it insists it is doing what it can and paying a heavy price, pointing to its deployment of more then 100,000 troops in its increasingly restive northwest and a wave of suicide bombings across the country.