A homicide attack at Pakistan's main army training base killed at least 42 soldiers Wednesday, the military said, and suspicion fell on pro-Taliban militants who had vowed revenge for a deadly helicopter attack on an Islamic school last month.

If it is confirmed that the Islamic militants carried it out, the attack would be the insurgents' deadliest yet against the Pakistani army.

"A man wrapped in a cloak came running into the training area and exploded himself where recruits had gathered for training," the army said in a statement.

Information Minister Mohammed Ali Durrani said 42 soldiers died and 20 were injured. He said about 200 soldiers had formed up for morning exercises when the attack occurred.

"This is a contemptible act and everyone should condemn it," Durrani said in Islamabad.

Shortly after the attack in Dargai, a town in the North West Province that borders Afghanistan, security agents captured a suspected accomplice of the bomber after chasing him into a nearby village, an intelligence official said on condition of anonymity because he was not authorized to speak to the media.

The official did not reveal the identity of the suspect, and only said he had been moved to an army detention facility for questioning.

The military has been waging a campaign to clear pro-Taliban militants from the border region, which it says is used as a staging area for attacks in Afghanistan.

No one claimed responsibility for the attack in Dargai, but the town is considered a stronghold of the outlawed Islamic group Tehrik-e-Nifaz-e-Shariat Mohammadi, which has been fighting government forces in the tribal regions bordering Afghanistan since 2002.

Lal Zaman, a 25-year-old resident of the area, said he was sitting at a nearby shop when an explosion went off.

"The sound of the blast shocked me for a minute, but I ran toward the army camp after seeing dust and smoke and hearing cries," he told The Associated Press. "I saw body parts and injured everywhere on the ground where the soldiers do their morning exercise every day."

The drill area where the attack happened is not fenced off. It is only surrounded by trees and bushes. Inside the grounds, an AP reporter saw officers collecting shoes and other belongings of the dead and injured soldiers.

Another official said they had launched a search to capture other accomplices.

"We have some important clues about the attackers, but this information cannot be shared with the media," the official said on condition of anonymity because he was not allowed to speak with the press.

Dargai lies about 45 miles northwest of the Bajur tribal region, where an Oct. 30 military raid on an Islamic school killed 80 people and sparked furious protests across the country.

Pakistan's government said the school served as a front for training militants. Local people and an Islamic opposition party said that almost all the victims were children or teenagers studying at the school.

Some Tehrik-e-Nifaz-e-Shariat Mohammadi members, including its fugitive leader Faqir Mohammed, attended a mass funeral last week for those slain in the school attack. Mohammed vowed to retaliate with suicide bombers.

Mohammed has been the target of an army manhunt in recent years for allegedly sheltering al-Qaida militants.

Pakistan's Interior Minister, Aftab Khan Sherpao, condemned Wednesday's attack and said: "It is linked to the Bajur incident," he said.

Local community leaders and lawmakers have said that U.S. military drones initiated the attack on the school, a claim Pakistan and U.S. officials deny.

Pakistan is a key ally of the United States and has deployed about 80,000 troops in the country's tribal area. Osama bin-Laden is believed to be hiding somewhere in the area.