BAC NINH, VIETNAM • A baby boy and a five-year-old girl were killed in an explosion east of Vietnam's capital Hanoi that destroyed several houses and wounded at least eight other people.

The authorities are investigating the cause of the blast in Bac Ninh province's Yen Phong district, which occurred at 4.30am yesterday, demolishing buildings and sending debris flying through the air.

The explosion reduced four homes to rubble and shattered the windows of surrounding buildings.

A one-year-old boy and a girl were killed, according to a report from the provincial health department.

At least eight others were injured by the blast, district authorities said in a statement.

Local resident Nguyen Thi Tap said her house was badly damaged by the explosion, which jolted her from her sleep.

"I thought thunder had struck my roof... I hugged my daughter and the doors crashed down on us," she said.

According to a local official, who requested anonymity, the explosion took place in an area "where there are many families involved in collecting scrap (metal)".

The salvage of metal from the tonnes of Vietnam War-era bombs that still blanket the country often ends in tragedy. In August, six people were killed when a war-era bomb exploded in Kanh Hoa province. Reports suggested it detonated as scrap workers cut it open.

Since the end of the Vietnam War in 1975, more than 42,000 people have been killed and over 62,100 injured by unexploded ordnance, according government figures.

AGENCE FRANCE-PRESSE