Police said it was too early to say whether the explosions were the result of a militant attack like those that killed 12 people at the Jakarta Marriott in 2003 and more than 200 in Bali in 2002.

President Susilo Bambang Yudhoyono, who was re-elected to a second term in the mainly Muslim country last week, was "deeply concerned over the incident," a spokesman for his office said,on twin bomb explosion early morning in capital city Jakarta.