Simultaneous power outages yesterday blacked out large parts of peninsular Malaysia for several hours, disrupting flights at the country's main airport, trapping people in elevators and causing traffic snarls.

　　The main outage began at around 10 am in five states in peninsular Malaysia, said Pian Sukro, chief executive officer of Tenaga Nasional, Malaysia's main power utility company.

　　Officials ruled out sabotage as the cause, but were investigating an unexplained glitch that damaged the power distribution system during maintenance work on a major cable line, Pian told a news conference.

　　Large-scale electricity failures are rare in Malaysia. The blackout yesterday was one of the worst since August 1996, when nearly all of peninsular Malaysia was hit by an outage that lasted about 14 hours.

　　Prime Minister Mahathir Mohamad ordered a complete investigation.

　　"There were recent blackouts in New York and London, so it's our turn now," Mahathir told the national news agency, Bernama. "We must find out why it happen-ed and study the reasons to prevent it from happening again."

　　Engineers repaired the damaged cables and restored electricity to most affected areas within five hours on Monday, officials said.

　　A separate outage blacked out the entire Kuala Lumpur International Airport for 10 minutes before power was restored in stages over nearly two hours, said the airport's general manager Abdul Hamid Ali.

　　Six flights, including departures to London and Singapore, were delayed for up to a half-hour, while ticketing and luggage handling facilities were also temporarily disrupted, Abdul Hamid said.

　　The 10,000-hectare airport opened in June 1998 to accommodate millions of passengers and faster jets so that Kuala Lumpur could compete as an aviation hub with neighbors Bangkok and Singapore.

　　Tenaga Nasional said the airport blackout was not related to the rest of the outage - although the events occurred at the same time - because the airport obtains its electricity from a different supplier. It was not immediately clear what caused the airport blackout.

　　Police were deployed to direct traffic and relieve road congestion in some cities because traffic lights were not functioning, witnesses said. Firefighters in northern Penang state received more than 20 phone calls to rescue people trapped in elevators, local media reported.

　　Banks and many offices were closed for a public holiday in conjunction with Malaysia's National Day, which was celebrated on Sunday. Hospitals, gasoline stations, road toll plazas, shopping malls and businesses relied on backup generators.