CHARSADDA, Pakistan - A suicide bomber killed at least 38 people in a mosque in northwest Pakistan on Friday where a former interior minister was offering Muslim Eid festival prayers with worshippers, officials said.

Intelligence officials said as many as 50 people may have died when the attacker detonated explosives inside the mosque but the number could not be immediately confirmed by police.

Aftab Ahmed Khan Sherpao, who was interior minister in President Pervez Musharraf's recently dissolved government and who is now running in January 8 parliamentary elections, was the likely target of the attack at the mosque in his home village, the government said.

Sherpao, who heads a small pro-Musharraf political party, escaped unharmed but his son was injured. Sherpao had been injured in April in another suicide attack at a public meeting in Charsadda.

At least 40 people were wounded in the blast on Friday. Body parts and shoes were scattered around the mosque floor covered in pools of blood and police found parts of a jacket, believed to belong to the attacker, and ball bearings aimed at causing maximum damage.

The suspected bomber, sitting in a middle row among the worshippers, detonated his bomb as prayers ended and people gathered around the politician to greet him, a police official who asked not to be named, said.

Around 1,200 worshippers were at the mosque at the time of the explosion.

"At the moment we have 38 confirmed dead and 40 wounded," Federal Secretary of Interior Syed Kamal Shah told Reuters.

"We feel that Sherpao was the target. There are so many mosques in that area. Why did the bomber select that mosque for the attack?"

The district is about 20 km (12 miles) from Peshawar, the provincial capital.

"It was a huge explosion," said Mohammad Mukhtiar, a worshipper in the mosque.

There have been a rash of suicide attacks blamed on Islamist militants since a military assault on the Red Mosque, a militant stronghold, in Islamabad in July.

More than 800 people have been killed in the ensuing violence across the country, with about half of them killed in suicide attacks.

Musharraf, a key ally in the U.S.-led war on terrorism, cited growing militancy as a main reason behind his imposition of emergency rule on November 3.

Musharraf, who said hours after lifting emergency rule last weekend that the government had "broken the back" of the militancy, condemned Friday's attack.