KABUL (July 9, 2009)--A massive blast in central Afghanistan has killed 25 people, including 21 civilians and four policemen, an Interior Ministry official says.

Zemerai Bashary said the powerful blast also destroyed nearby shops lining the road in the central Logar province.

The provincial police chief, Mustafa Khan, says the blast happened after a truck filled with timber tipped over on the main road connecting Logar province with Kabul to the north.

The blast happened as thousands of U.S. Marines in southern Afghanistan are involved in the biggest American military offensive in country since the ouster of the Taliban from power in 2001.