Rescuers searched for survivors on Saturday after a powerful blast in Jalalabad killed at least 26 people and knocked out power to the eastern city, stoking fears about Afghanistan's volatile security climate. Provincial officials said stored explosives at the Afghan Construction and Logistic Unit (ACLU) on the outskirts of Jalalabad could have accidentally detonated, though military officials earlier speculated it was a terrorist bomb.

The massive explosion ripped apart dozens of mud-built homes near a hydro-electric dam, injuring at least 80 people, Kabul Radio said.

Afghan rescue teams had found 13 bodies by Saturday morning, laboriously digging through piles of rubble with rudimentary tools, rescue official Haji Nasrullah Baryalai said.

"Since dawn, people have resumed their search to see if they can find any survivors, as we don't know whether more people are caught under collapsed walls and timbers of houses or not," Baryalai told Reuters on phone.

State-run Kabul television put the death toll at 26.

Baryalai said dozens of wounded people were being treated in the city's hospital.

Power was cut throughout Jalalabad after the blast damaged the dam.

Baryalai said the explosion went off inside a room storing explosive devices used for road construction.

"For dynamiting ridges and hindrances along the roads, ACLU needed the explosive materials...," he said.

"There is a strong possibility that the blast was not an act of sabotage. Investigation continues to find if it was a sabotage incident, but so far we have found no clues to back up this speculation," Baryalai added.

The U.S. military quoted initial reports from U.S. officials in Jalalabad as saying a truck bomb caused the blast. Jalalabad, about 70 miles east of Kabul near the border with Pakistan and the capital of Nangarhar province, has long had a reputation as a center for heroin production.

Before the fall of the Taliban at end of last year, the outskirts of the city were dotted with training camps for the al Qaeda network of Saudi dissident Osama bin Laden, wanted by Washington for masterminding the Sept. 11 attacks.

Mohammad Qasim Fahim, defense minister of the Afghan government that replaced the Taliban, survived an assassination attempt recently while on a visit to Jalalabad.

And the region's most powerful warlord, Haji Abdul Qadeer was murdered in Kabul last month not long after he was appointed the country's vice president. The government in Kabul blames Taliban and al Qaeda followers for both incidents.

PHOTO CAPTION

More than 20 people were killed and many others wounded near the Afghan city of Jalalabad on August 9, 2002 in an explosion at an office of a non-governmental organization, an Afghan news agency reported. The Afghan Islamic Press (AIP) said the explosion happened at the offices of the Afghan Construction and Logistics Unit six miles west of the eastern city. It said the NGO was involved in road construction. (Reuters Graphic)