TEHERAN (AFP) - An explosion in a battery workshop near the Iranian capital on Friday (Sept 11) killed one person, injured 10 others and damaged apartment buildings and cars, Iran's state news agency IRNA reported.

The blast struck at 5.15pm (8.45pm Singapore time) on the ground floor of a three-storey residential building in Teheran province's Nasimshahr county, local fire brigade chief Iraj Torkamani told IRNA.

A fire triggered by the explosion "was so severe that a worker immediately died and 10 residents from 25 apartments in the building were lightly injured", he said.

More than 20 cars and some other nearby buildings were also damaged, he added.

Torkamani told Tasnim news agency that the cause of the explosion was still unclear and investigations were under way.

A local crisis management chief, Mansour Darajati, told state television that a malfunctioning cutting tool may have been the cause.

The broadcaster showed walls of a building's ground floor seemingly blasted open and several cars with broken windows damaged by falling debris.

The incident is the latest in a series of fires and explosions that have hit military and civilian sites across Iran since June.

On July 2, a building at Iran's Natanz nuclear complex was badly damaged, at the end of a week marked by two explosions in Teheran, including one near a military site.

Officials have said the blasts were accidents, but some Iranian media suspected covert Israeli operations were responsible.

Iran's Supreme National Security Council announced on July 3 that the "cause of the accident" at Natanz had been "accurately determined" but declined to elaborate for security reasons.

At the end of July, Mojtaba Zolnour, head of parliament's national security and foreign affairs committee, ruled out drone or missile attacks as the cause.