RAWALPINDI, Pakistan — Gunmen wearing military uniforms and wielding assault rifles and grenades attacked Pakistan’s army headquarters on Oct. 10, sparking a ferocious gun battle in which four assailants, two senior officers and four soldiers were killed, authorities said.

The attack began shortly before noon when the gunmen, dressed in camouflage military uniforms, drove up to the army compound in a white van and tried to force their way inside, army spokesman Maj. Gen. Athar Abbas said.

The assailants shot at the guards at one checkpoint, killing several, and then jumped out of the van and ran towards a second checkpoint, he said. Abbas said the guards were probably confused by the attackers’ uniforms.

After a 45-minute gunfight, four of the attackers were killed, said Abbas. The assault was declared over and the situation “under full control.”

However, more than an hour later, gunshots rang out from the compound, and Abbas confirmed that two gunmen who had eluded security forces slipped into the headquarters’ compound in Rawalpindi. The city, adjacent to the capital of Islamabad, is filled with security checkpoints and police roadblocks.

The audacious assault on Pakistan’s army headquarters was the third major militant attack in Pakistan in a week, and came as the government said it was planning an imminent offensive against Islamist militants in the rugged mountains along the border with Afghanistan.

Pakistani media said the Taliban claimed responsibility for the attack, and Interior Minister Rehman Malik said the ongoing assaults strengthened the government’s resolve to launch the offensive.