The bombing has raised security concerns around the world

The United Nations Secretary-General, Kofi Annan, expressed outrage over what he called an apparent act of terrorism.

"It was an atrocious act and this senseless killing of innocent civilians is something that cannot be condoned by any government," he said.

The US have said it remained confident in Jakarta's ability to rein in terrorism and protect US interests in the country.

But it repeated calls for its citizens in Indonesia to be vigilant in the aftermath of the blast, and pledged to help the Indonesian Government investigate.

White House spokesman Scott McClellan called the bombing "a deplorable attack on innocent civilians".

"This terrorist act... is a reminder that we are still waging a global war on terrorism," Mr McClellan said.

"The global coalition remains steadfast in our efforts to pursue terrorists and bring them to justice."

I am quite horrified at what appears to be a brutal terrorist attack John Howard, Australian Prime Minister

The Australian Prime Minister, John Howard, offered to send investigators to help Indonesia and warned of ongoing terrorist activity.

"I am quite horrified at what appears to be a brutal terrorist attack. If, as it appears likely, it is a terrorist attack, it is yet another reminder that the fight against Jemaah Islamiah and other groups goes on."

Philippine President Gloria Macapagal Arroyo joined in condemnation over the attack.

"This attack does not and cannot alter the resolve of the international community to fight terror."

The Chinese Government said it would support Indonesia's efforts to crack down on terrorism.