Workers at a scrapyard in Thailand's capital accidentally detonated a large bomb believed to have been dropped during the second world war, killing at least seven people and injuring 19 others, police said.
Police bomb squad chief Kamthorn Auicharoen said construction workers found the bomb buried at a building site and sold it to the scrapyard in northern Bangkok. He said workers were using a gas-powered thermal cutter to take the bomb apart when it exploded.
The massive blast ripped apart the scrapyard in Bangkok's Lad Prao district and damaged nearby houses.
"It's likely this is a bomb dropped from a plane during world war two," said Kamthorn.
Construction workers found a similar bomb in a different area of Bangkok last Saturday, but it was safely handed over to police explosive experts.
Bangkok was bombed by US and British planes during the second world war, when it was occupied by Japanese forces and served as a hub for their campaign in south-east Asia. Buried bombs from the era continue to be found from time to time in other major Asian cities, including Hong Kong and Singapore.