Pakistan - Suspected Taliban militants wearing army uniforms attacked the Pakistani army's headquarters on Saturday, killing six soldiers and triggering a battle in which four gunmen died, military officials said.

The brazen attack on the tightly-guarded headquarters in the city of Rawalpindi came as the military is preparing a major offensive against the militants in their northwestern stronghold on the Afghan border.

The gunmen drove in a white van with military license plates to a main gate of the complex before opening fire and throwing a grenade when challenged by soldiers. The gunmen then exchanged fire with troops for about 40 minutes.

Six soldiers, including a brigadier and a lieutenant-colonel who were passing through the gate, were killed. Four gunmen died but two escaped. Security forces later tracked the two gunmen down, a military spokesman said.

We have spotted them, we have surrounded them, and now an operation is being launched to clear them out, said the spokesman, Major-General Athar Abbas.

Al Qaeda-linked Islamist militants have launched numerous attacks in Pakistan over the past couple of years, most aimed at the security forces or government and foreign targets. Militants have attacked military targets in Rawalpindi before.

Television pictures showed the militants' van, its doors open, where the gunmen abandoned it by concrete barriers outside the gate.

The attack came a day after a suspected suicide car-bomber killed 49 people in the city of Peshawar in an attack which the government said underscored the need for the all-out offensive against the Taliban.

What happened in Peshawar, Islamabad and today, all roads lead to South Waziristan, said Interior Minister Rehman Malik, also referring to a suicide bomb attack on a U.N. office in Islamabad on Monday.

The TTP is behind all of these attacks and now the government has no other option but to launch an offensive, he said, referring to the Taliban Movement of Pakistan based in the South Waziristan region on the Afghan border.

PUNJAB MILITANTS

Early this year, militants pushed to within 100 km (60 miles) of Islamabad, raising fears for nuclear-armed Pakistan's stability. An exasperated U.S. Secretary of State Hillary Clinton said the government appeared to be abdicating to the militants.

The United States needs Pakistani help against militants crossing into Afghanistan to battle U.S.-led forces there.

But in late April the security forces launched an offensive in the Swat valley, 120 km (80 miles) northwest of Islamabad, largely clearing Taliban from the region.

The militants suffered another big blow on August 5, when their overall leader, Baitullah Mehsud, was killed in a missile attack by a U.S. drone aircraft in South Waziristan.

The United States and India have also called for action against Afghan Taliban factions on the border and anti-Indian militant groups based in Pakistan's Punjab province.
North West Frontier Province Information Minister Iftikhar Hussain called for the elimination of militant bases in Punjab, telling reporters that even if an offensive were successful in South Waziristan, militants would get support from Punjab.

The government ordered the army to go on the offensive in South Waziristan in June and security forces have been launching air and artillery strikes, while moving in troops, blockading the region and trying to split off factions.

The army has declined to say when it would send troops in.

(Additional reporting by Kamran Haider and Sheree Sardar; Writing by Robert Birsel; Editing by Jerry Norton/David Stamp)

Pakistan