SUKABUMI: A 5.9-magnitude earthquake struck Indonesia's most-populated island on Monday, seismologists said, but there were no immediate reports of damage or casualties.

The quake struck 96 kilometres (59 miles) southwest of Sukabumi in western Java after 6:00 pm (1100 GMT) at a depth of 67 kilometres, the US Geological Survey said.

"The quake was quite strong but we have no reports yet of casualties or damage. We will monitor the affected area," National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho said.

Nugroho said the quake struck around 50 kilometres offshore and that activities in Sukabumi had "gone back to normal".

An AFP correspondent in Sukabumi said the quake lasted around three minutes and that residents ran from their homes in panic.

The quake was also felt in the capital Jakarta around 200 kilometres northeast of the epicentre.

The Indonesian Meteorological and Geophysics Agency earlier measured it as a 6.1-magnitude quake with a depth of 24 kilometres.

Indonesia sits on the Pacific "Ring of Fire" where continental plates collide, causing frequent seismic and volcanic activity. (AFP)

BEIJING (Reuters) - Three of China's largest Internet companies have promised the government they will take steps to banish online rumors, state media said on Tuesday, as the ruling Communist Party fights jitters over a tricky leadership transition.

A dispatch by the official Xinhua news agency made no mention of rumors of a foiled coup in Beijing that spread on the Internet in past weeks, after the abrupt ousting of Bo Xilai, a contender for a spot in the new central leadership to be unveiled at a party congress later this year.

But the article was the latest in a series carried by state media lambasting online rumors and those who spread them.

The March 15 ouster of Bo as party chief of the inland city of Chongqing, linked to a scandal involving a senior aide, has shaken the party ahead of the leadership changes.

After Bo was sacked, popular microblogs, including those run by Sina Corp. and Tencent Holdings Ltd, were awash with speculation about a coup.

Xinhua said that both companies, along with top search engine Baidu Inc, would "resolutely support and cooperate with relevant government departments in measures to fight and clear up online rumors".

They would also "earnestly fulfill their responsibility to society, follow the law, increase management of the Internet and adopt effective measures" to guard against rumors.

While the coup rumors were unfounded, their spread and the tightening of Internet controls and warnings to ignore such talk have reflected worries about stability after Bo's fall.

Last week, China's top military newspaper told troops to ignore online rumors.

And in late March, authorities shut 16 Chinese websites and detained six people accused of spreading rumors about unusual military movements and security in the capital.

The rumors fed on speculation about the ousting of Bo over a month after his vice mayor, Wang Lijun, fled to a U.S. consulate, triggering a scandal exposing accusations of infighting and abuses of power.

A St. Louis museum can keep hold of a 3,200-year-old mummy's mask, a federal judge has ruled, saying the U.S. government failed to prove that the Egyptian relic was ever stolen. 

Prosecutors said the funeral mask of Lady Ka-Nefer-Nefer went missing from the Egyptian Museum in Cairo about 40 years ago and that it should be returned to its country of origin. 

The St. Louis Art Museum said it researched the provenance of the mask and legitimately purchased it in 1998 from a New York art dealer. 

U.S. District Judge Henry Autry in St. Louis sided with the museum. 

The U.S. government "does not provide a factual statement of theft, smuggling or clandestine importation," Autry wrote in the March 31 ruling. 

"The Government cannot simply rest on its laurels and believe that it can initiate a civil forfeiture proceeding on the basis of one bold assertion that because something went missing from one party in 1973 and turned up with another party in 1998, it was therefore stolen and/or imported or exported illegally," the judge wrote. 

A message left with Egypt's Supreme Council of Antiquities was not returned. 

The 20-inch-long funeral mask of painted and gilded plaster-coated linen over wood with inlaid glass eyes was excavated from one of the Saqqara pyramids, about 16 miles south of Cairo, in 1952. 

Ka-Nefer-Nefer was a noblewoman who lived from 1295 BC to 1186 BC. 

U.S. government investigators suspect the mask was stolen sometime between 1966, when it was shipped to Cairo for an exhibit, and 1973, when the Egyptian Museum discovered it was missing. 

The art museum bought the mask in 1998 for $499,000 from a New York art dealer, and it has been on display at the museum in Forest Park ever since. 

U.S. Attorney Richard Callahan said a decision on whether to appeal has not been made. 

"We're just looking to make sure we haven't missed the tiniest bit of circumstantial evidence," Callahan said. "We're back to the drawing board and studying it." 

Museum officials have said they researched the mask's ownership history before buying it and had no indication there were questions about how it arrived in the U.S. The museum's research showed the mask was part of the Kaloterna private collection during the 1960s, before a Croatian collector, Zuzi Jelinek, bought it in Switzerland and later sold it to Phoenix Ancient Art of New York in 1995. The art museum purchased the mask from Phoenix Ancient Art. 

St. Louis Art Museum attorney David Linenbroker said the museum is confident the ruling will mean that the mask can remain permanently in St. Louis. 

"We don't have any interest in possessing a stolen object," Linenbroker said. "We've been facing all this innuendo for years." 

He said the legal process provided an opportunity for someone to prove the mask had been stolen, but no one did. 

"We're confident we're the rightful owner," Linenbroker said.