Fox News website says it was a meteor.
JAKARTA, Indonesia (AP): A loud noise that several witnesses said resembled an explosion was heard in parts of Jakarta early Sunday. Media reports said a meteor had fallen close to the capital.
Several callers to el-Shinta radio station reported a noise that sounded like an explosion at around 7.30 a.m in western districts of Jakarta. Metro TV station reported that a large object, suspected to be a meteor, had fallen to earth, also to the west of the city.
Police said they were investigating the reports, but they had no reports of any bombings in the capital.
No other details were immediately available.
Dozens of people telephoned Jakarta's ElShinta radio to describe an object, white in appearance, crossing the sky west of Jakarta and a violent noise followed by what they said sounded like an echo.
The explosion could be heard in Tangerang, just west of Jakarta, the southern suburb of Depok and as far away as Bogor, some 60 kilometers (35 miles) south of the capital.
"It is difficult to say what it was because there were no clear timings between the sighting and the blast, but from what the various accounts said, it is very likely to have been a falling meteor," said astronomer Muji Raharto.
Hours after the sightings were reported at around 7:30 am (0030 GMT) it was still unclear what the object was or where it exploded.
Police said they had no reports of any fallen objects and said they were still investigating the origin of the explosion.
"We have called all sub-districts and they all say they are not aware" of a falling meteor in their area, a female officer on duty at the Tangerang district police, First Inspector Kamtini told AFP.
Raharto said later that if witnesses' accounts were correct, it could have been a ball of gas some 1,000 meters (3,300 feet) in diameter enveloping a much smaller solid core.
The blast, he said, could have come from the core exploding as it underwent a rapid temperature rise due to friction.
"The fallout would have been small pieces, that could easily go unnoticed in unpopulated areas," he said, explaining the absence so far of any evidence of a large impact.
Air force spokesman First Air Marshal Sagom Tambun said the air force was not monitoring falling objects such as meteors.
"Our radars are only for detecting and monitoring horizontal moving objects in the sky, and only then are we interested if the object suddenly moves on the vertical," Tambun said, adding he had had no reports of any observation of a falling object in the sky so far.
Indonesia's security forces have been on alert after warnings from western governments that Islamic militants blamed for a series of deadly bombings in the country were planning an imminent attack in the run-up to Christmas.
Meanwhile, meteorologists in both Jakarta and Tangerang said there had been no seismic irregularities registered in the areas. Officials at Jakarta's international airport said their radars were incapable of picking up meteors.
Raharto, from the Boscha astronomical observatory in Bandung, West Java, told AFP that only specialised radars could detect falling space debris. He said the country's only operational specialised radar was in Bukittinggi, West Sumatra, too far from the sighting sites.