PRAGUE - US Secretary of State Hillary Clinton Friday condemned "senseless" bomb attacks in two Jakarta hotels that killed at least nine people, underlining that the threat of terrorism remains "very real."

The State Department was working "to help American citizens injured in the blasts" in the Indonesian capital, Clinton said in a statement issued from Prague as her plane stopped for refuelling en route to India.

"We condemn these senseless acts of violence and stand ready to provide assistance if the Indonesian government requests us to do so," she said.

"The attacks reflect the viciousness of violent extremists, and remind us that the threat of terrorism remains very real," Clinton said, offering her sympathies to the victims and the Indonesian people.

"We have no higher priority than confronting this threat along with other countries that share our commitment to a more peaceful and prosperous future."