The police today tightened security around foreign embassies after a small explosive device was thrown at the Australian High Commission from a speeding car, officials said.

The bomb caused no injuries or damage to property after hitting the front fence of the high commission in central Kuala Lumpur and exploding, Australian Deputy High Commissioner Simon Merrifield told AFP.

He declined to speculate on whether it was a terrorist incident or the expression of some personal grudge against Australia.

"The matter is being investigated by police and as far as we are aware there are no leads at the moment."

Merrifield described the attack as "a minor incident involving a small improvised explosive device being thrown from a car at ten to five this morning .

"It was thrown at the front fence of the high commission. It exploded with a big bang but caused no damage to life or property." It was not immediately clear what explosive the device contained.

The attack was witnessed by police and private security personnel guarding the embassy and the bomb squad and fire brigade were quickly on the scene, he said.

Security at the embassy was already tight in the wake of terrorist attacks around the world and "we will maintain our high level of vigilance," Merrifield said.

The high commission remained open to the public throughout the day and it was "business as usual," he said.

Captured on CCTV

A senior aide to Prime Minister Abdullah Ahmad Badawi told AFP: "We are concerned. The police are investigating immediately. We were told initially that it was a very small explosive and the incident was captured on the (security) video camera.

"We don't want to raise any alarm bells. It could be an isolated incident but we don't want to rule out anything at this point.

"Obviously there is nothing that indicated this was going to take place as far as the known terrorist networks are concerned."

He said security patrols for the diplomatic community in Kuala Lumpur would be stepped up.

Australia a key US supporter

Malaysia has had no terrorist attacks against foreign targets on its own soil, but has detained more than 80 alleged Islamic militants in recent years, accusing them of membership in local and regional terror groups.

Some are said to belong to the Malaysian Mujahidin Group (KMM), allegedly plotting the violent overthrow of the government, and others to the Jemaah Islamiah (JI) organisation responsible for the Bali bombings in neighbouring Indonesia in October 2002.

More than 200 people were killed in that attack, 88 of them Australian holidaymakers.

JI is linked to Osama bin Laden's Al-Qaeda network, which was behind the September 11 attacks in the United States and which is purported to have claimed responsibility for the Madrid bomb attack that claimed more than 200 lives.

The incident at the high commission here comes two days after Australia - which like Spain supported the US-led invasion of Iraq - announced plans to step up its war on terror.

Prime Minister John Howard announced Sunday that the government would expand its key intelligence agency and bolster anti-terrorism powers under new laws approved by the cabinet. - AFP