RAWALPINDI: Taliban militants were holding several security officers hostage inside Pakistan`s army headquarters on Saturday after they and others attacked the complex in an audacious assault on the country`s most powerful institution.

The attack, which left at least 10 people dead, was the third major militant strike in Pakistan in a week and came as the government was planning an imminent offensive against Islamist militants in their strongholds in the rugged mountains along the border with Afghanistan.

It showed that the militants retain the ability to strike at the very heart of Pakistan`s security apparatus despite recent military operations against their forces and the killing of Taliban leader Baitullah Mehsud in a CIA drone attack in August.

An army statement said more than two terrorists were holding several officers hostage in a ``security office building`` inside the heavily fortified complex close to the capital.

The whereabouts of military chief Gen. Ashfaq Parvez Kayani was not known. Separate army statements said he had attended meetings at the headquarters and at the president`s office in nearby Islamabad during the day.