Indonesian anti-terrorist police say they have arrested 11 suspected Islamist militants before they attacked the US embassy.
Bomb-making equipment was seized, along with one device ready for use by a new group, Harakah Sunni for the Indonesian Society.
Javan Police say they planned to attack the embassy, a consulate, a square opposite the Australian embassy, and a mining company.
The arrests are the latest in a crackdown against Islamic militants that has led to dozens of arrests and at least seven killed in gunbattles.
This month is the tenth anniversary of the Bali bombings, when 202 people, mostly foreign tourists, died.