A bomb killed at least 29 people and wounded 37 on Tuesday when it exploded near a fuel station in Pakistan's northwestern Khyber region, one of the restive tribal areas where insurgents are battling government forces, regional officials said.

It was a huge blast and caused damage to a number of vehicles at (a) bus terminal, said Khyber tribesman Khan Zaman from the Jamrud bazaar, around 25 km (15 miles) west of the city of Peshawar.

Government officials in the area said 29 people were killed and 37 wounded, at least 20 of whom are in critical condition.

Tribesman said members of the pro-government Zakhakhel tribal militia were the target of the attack. Members of the militia -- or lashkar -- were filling their vehicles at the station when the bomb exploded.

There was a loud explosion, everything shook, said Fariz Ullah, a fruit seller in Jamrud near the fuel station.

We all ran to the station. There were bodies everywhere. I saw bodies missing hands and feet, he said.

Assistant Political Agent Jamrud Mohammad Jamil Khan said three members of the Khasadar tribal police force were among those killed.

The wounded were taken to hospitals in Jamrud and Peshawar.

Officials said there had been no claim of responsibility yet for the attack. Pakistani forces have targeted militants in Khyber, including the Pakistani Taliban, on and off for more than four years.

Tuesday's bombing is the first major one of its kind this year. On December 30, 13 people were killed in a bombing in the southwestern city of Quetta. On August 19, 2011, a suicide bomber killed at least 48 people inside a mosque in Jamrud.

The attack also comes amid conflicting reports of peace talks between the Tehrik-e-Taliban Pakistan (TTP) and the Pakistani government.

The TTP, formed in 2007 and allied with the Afghan Taliban, is an umbrella group of militant organisations entrenched in Pakistan's unruly tribal areas along the porous frontier with Afghanistan.

It has pledged to overthrow the Pakistani government after the military started operations against the militants in 2007.

(Additional reporting by Ibrahim Shinwari; Editing by Chris Allbritton and Paul Tait)