A car bomb blast on Friday killed up to 41 people in the northwest Pakistani city of Peshawar, the capital of North West Frontier Province (NWFP), provincial minister and local police said.

Police said the bomb blast took place in a bus at the Khyber Bazaar nearing the NWFP assembly in Peshawar. The market was shut down after the explosion.

The car bomb blast killed at least 41 people, NWFP Health Minister Zahir Ali Shah said. Shah told reporters that around 100 people were injured and 15 are in critical condition.

Earlier, Provincial Information Minister Mian Iftikhar Hussain told reporters that the explosive-filled car was parked at the crowded Khyber Bazaar and the terrorists targeted the civilians.

Assistant Inspector General of the Bomb Disposal Squad, Shfaqat Malik, said that high intensity of explosives was used in the blast. He hinted that it might be a suicide attack.

The injured were taken to the Lady Reading Hospital and emergency was declared to treat the injured.

Women and children were among those killed and injured in the deadliest blast in recent months.

Ambulances of government hospitals and private relief groups rushed to the blast site and shifted the injured to hospitals.

No group claimed responsibility for the blast. But the information minister blamed militants for the attack.

It is the second blast in Peshawar in less than two weeks. On September 26, a car bomb in Peshawar killed at least 8 persons.

"We will not bow before the terrorists," Hussain told reporters at the blast site. He said the government has broken the back of the terrorists and now they are targeting human beings.

An official of the bomb disposal squad told reporters that 100 to 150 kilogram explosives were used in the blast. He said the explosives-filled white car on the way to hit a target but exploded near a passenger mini-bus.

Pakistani Prime Minister Yousuf Raza Gilani strongly condemned the Peshawar blast and ordered immediate enquiry into the incident and best medical facilities for the injured.

He said that such activities can not deter the government from its action against the extremists and action will continue till their complete elimination.

Peshawar District Police Officer Sahibzada Anis said that the security agencies are investigating and if it was security lapse, the responsible will be punished.

The bomb blast destroyed several vehicles and smashed windows of many buildings including banks, shops and offices.

The attack in Peshawar came as Pakistan's army prepares for another major operation in the Al-Qaeda and Taliban stronghold of South Waziristan tribal region. The militants have threatened bombings if the army doesn't back off, but the United States has continued to prod Pakistan to take action against insurgents using its soil to fuel the insurgency in neighboring Afghanistan.

It came days after a suicide attack killed five on Monday at a UN office in the capital Islamabad. Pakistani Interior Minister Rehman Malik said Friday that the law enforcement agencies have arrested the main handler of the attack on the UN World Food Programme office in Islamabad.

The attack also came amid growing tensions between the US and Pakistan over a multi-billion-dollar US aid package that is aimed at helping Pakistan's economy and other non-military sectors.