The U.S. Embassy (searchissued a fresh warning to Americans in Indonesia on Friday, saying the risk of terror attacks over Christmas and New Year was "particularly high."

"The embassy reminds all Americans in Indonesia of the increased volatility of the security environment during the holiday season," read a statement posted on the embassy's Web site.

Islamic militants bombed several churches in Indonesia on Christmas Eve three years ago, killing at least 19 people and wounding scores.

The statement said there was a "particularly high" potential for attacks on hotels, clubs, restaurants, shopping centers, housing compounds, transportation systems, places of worship, schools and outdoor recreation events.

Indonesia, the world's most populous Muslim nation, has emerged as a key battle ground in the war on terror in recent years.

On Oct. 12, 2002, suspected members of the Al Qaeda (search)-linked terror group Jemaah Islamiyah bombed two nightclubs on Bali (search) island, killing 202 people, mostly foreign tourists.

The same group has been blamed in the Aug. 5 bombing of the J.W. Marriott hotel in Jakarta, which killed 12 people.

Despite several high profile arrests, the government has warned that the group is planning more attacks in the coming months.

Since the Bali blasts, more western governments have advised their citizens not to travel to Indonesia, citing the risk of further attacks.