Jakarta – A series of explosions rocked the parking lot of a busy shopping centre in the Indonesian capital of Jakarta on Sunday morning, police said.

The blasts caused moderate damage but there were no immediate reports of injuries and the cause of the blasts was not known. A bomb exploded in the same shopping centre on August 1.

"There were three bomb-like explosions which we think came from a car. The explosions were very loud but it seems the damage is not severe," a policeman at the site, who did not wish to be identified, told reporters. Witnesses said seven cars were badly damaged by the blasts on the second level of the parking lot.

A police official earlier told Reuters the blasts struck the Atrium Mall complex in the central Senen district at 10.45 am. The official had said the blasts occurred in the basement, but the parking lot is above ground.

A bomb hit the same shopping complex less than two months ago, wounding at least five people, and police linked it to a small group of Malaysian Muslim hardliners. Police had said the group was also involved in Muslim-Christian clashes in Indonesia's eastern Moluccas islands, where thousands have died in more than two years of savage violence.

There have been several unsolved bomb attacks in Indonesia in the past year amid political tension that climaxed in the ouster of the country's first democratically-elected leader, Abdurrahman Wahid, by the top legislature two months ago. Indonesians hope the appointment of Megawati Sukarnoputri as president will usher in some stability in the crisis racked country.

Sunday's blasts comes in the wake of threats of violence by Indonesia's Muslim radicals if the United States launches military operations in Afghanistan, in response to the September 11 attacks on its key cities.

Indonesia, which has the world's largest Muslim population, is largely moderate but hardline Islamic groups have emerged in recent years.