At least 13 people were killed and nearly 150 wounded on Tuesday when a car bomb exploded outside the Marriott Hotel in downtown Jakarta.
At least one foreigner, a Dutch citizen, was reportedly among the dead.
Witnesses, according to a news agency, described black smoke billowing from the front of the Marriott, which has been a regular venue for reception held by the US embassy.
Indonesia's Vice President Hamzah Haz said the attack may have been targeted against US interests in the country.
No group immediately claimed responsibility for the bombing. But since last year's blasts in Bali, which killed 202 people, authorities have warned that more attacks were likely in Indonesia -- possibly by Jemaah Islamiyah, the southeast Asian terror group linked to Al Qaeda.
Agencies