The US Embassy on Thursday in Indonesia has warned of a possible terrorist attack on the Bali island on New Year's Eve.
The embassy sent e-mails to US citizens quoting Bali's governor as saying "There is an indication of an attack to Bali tonight."
The warning comes six months after twin suicide blasts killed seven people at luxury hotels in the capital, Jakarta.
The resort island of Bali has been hit hard by Islamic terrorists, with more than 220 people killed in suicide bombings in 2002 and 2005 targeting Westerners.
The governor called on people to be alert, but gave no details about a specific threat.
Indonesia's counterterrorism unit says it received the warning but could not independently verify its accuracy.