RAWALPINDI, Pakistan, (Reuters) – Pakistani  commandos stormed a building near army headquarters yesterday  and freed 22 hostages being held there by suspected Taliban  militants, a military spokesman said.

Three hostages and four of the gunmen were killed, said the  spokesman, Major General Athar Abbas.

“They were in a room with a terrorist who was wearing a  suicide jacket but the commandos acted promptly and gunned him  down before he could pull the trigger,” Abbas said. “Three of the hostages were killed due to militant firing,”  he said.

Soldiers were searching for other gunmen in the building,  he said, adding there were believed to have been more than five  of them there.

Yesterday’s brazen attack on the tightly guarded  headquarters in the garrison city of Rawalpindi came as the  military prepared a major offensive against the militants in  their northwestern stronghold of South Waziristan on the Afghan  border.

The strike at the heart of the powerful military is likely  to revive fears for nuclear-armed Pakistan’s stability at a  time when the United States needs its help in the campaign  against an intensifying insurgency in Afghanistan.

A blast and gunfire erupted before dawn as soldiers  assaulted the security office building near the army  headquarters where the gunmen and their hostages were holed up. A Reuters reporter saw three ambulances leaving the area.

Gunmen wearing army uniforms attacked the army headquarters  yesterday killing six soldiers in a gun battle at a main gate  of the sprawling complex.

Four of the gunmen were killed and two of their wounded  colleagues captured in the initial attack, security officials  said. But other gunmen fled and took hostages in the office  building nearby.

Pakistani Taliban militants linked to al Qaeda have  launched numerous attacks in Pakistan over the past couple of  years, most aimed at the government and security forces,  including bomb attacks in Rawalpindi.

On Monday, a suicide bomber attacked a U.N. office in  Islamabad, and on Friday a suspected suicide car-bomber killed  49 people in Peshawar — an attack 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,” Interior Minister Rehman Malik said  yesterday. “Now the government has no other option but to  launch an offensive.”