JAKARTA, Indonesia —  A loud noise that several witnesses said resembled an explosion was heard in parts of Jakarta (search) early Sunday.

Media reports said an object that might have been a meteor (search) was seen flashing across the sky above the capital, but did not make clear if it had hit the earth.

Several callers to el-Shinta radio station reported a noise that sounded like an explosion at around 7:30 a.m. in western Jakarta.

Metro TV station reported that a large object, believed to be a meteor, was seen falling toward the earth at around the same time, also to the west of the city. The report did not say whether the object had hit the ground.

Police said they were investigating, but had no report of any bombings in or near the capital, or of any objects falling from the sky.

No other details were immediately available.

Police have been on high alert in Indonesia in recent days after several foreign governments reported that Islamic militants (search), blamed for a series of attacks in recent years, were planning more bombings.

On Saturday, the U.S. State Department warned that terrorists were planning attacks on Western targets in Indonesia over Christmas and New Years.