At least five people have been killed and several more injured in an apparent attack on the office of the Pakistani government's political agent in the northwestern city of Peshawar.

Explosions and gunfire were heard during Monday's attack on the compound of Muttahirzeb Khan, who is the government's representative in the region's tribal areas.

The victims are mostly security officials, witnesses said.

Officials said that two suicide bombers entered the compound, where a meeting of tribal and government officials was being held. After shooting was heard, two large explosions rattled the compound.

"We were holding a meeting and some others were joining us when firing started inside the political compound, and then there was a heavy blast, and again heavy firing began," Niaz Ahmad Khan, a tribal politician, said.

"We were told by the officials to take shelter inside the office as the terrorists had attacked the political compound."

He said he saw two bodies and some injured people lying on the ground inside the compound.

Khalid Mumtaz Kundi, one of Khan's deputies who was visiting from Khyber Agency, was injured in the attack.

Religious and sectarian armed groups have stepped up attacks across Pakistan just months before a national election.

On Saturday, 85 people, most of them Shia Muslims, were killed in the southwestern city of Quetta in an attack blamed on a pro-Sunni sectarian group.

And on Friday, Ameer Haider Khan Hoti, hief minister of Khyber Pakhtunkhwa, the northwestern province of which Peshawar is the capital, escaped a Taliban assassination attempt en route to a political rally in the town of Mardan.

There was no immediate claim of responsibility for Monday's Peshawar attack. But the Pakistani Taliban has carried out similar operations.

Some officials suggested the group staged the attack to free detainees; unconfirmed reports indicated that some prisoners may have escaped.