A powerful 8.6-magnitude earthquake and strong aftershocks struck off Indonesia on Wednesday, sending people as far away as southern India scurrying from buildings and raising fears of a disastrous tsunami as in 2004.

A tsunami watch was issued for countries across the Indian Ocean after a massive earthquake hit waters off Indonesia on Wednesday, triggering widespread panic as residents along coastlines fled to high ground in cars and on the backs of motorcycles.

Some were screamed "God is great" as they poured from their homes. Others, separated from relatives, cried as they ran frantically through the streets.

The US Geological Survey said the 8.6-magnitude quake was centered 3 kilometers beneath the ocean floor around 434 km from Aceh's provincial capital.

The tremor was felt in Singapore, Thailand, Bangladesh, Malaysia and India. High-rise apartments and offices on Malaysia's west coast shook for at least a minute.

The Pacific Tsunami Warning Center in Hawaii said a tsunami watch was in effect for Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, the Maldives and other Indian Ocean islands, Malaysia, Pakistan, Somalia, Oman, Iran, Bangladesh, Kenya, South Africa and Singapore.

Some countries, including Thailand, India and Sri Lanka, lifted their tsunami warning later on Wednesday.

It will not have a disastrous effect on China in the short term, though the situation must be closely monitored, according to a tsunami monitoring report released by the China National Marine Environmental Forecasting Center on Wednesday.

Fu Cifu, a forecaster in the center, warned Chinese tourists and residents in the affected region to stay in safe areas.

Two Shanghai Airlines flights heading from Shanghai Pudong Airport for Phuket Island, off the southwest coast of Thailand, due to take off at 9:15 pm and 20:15 pm, were cancelled immediately. However, the flights heading for Bangkok were about to take off according to schedule.

"We have a tour group setting off on Thursday, but so far we have not received any notice from the Shanghai Municipal Tourism Administrative Commission. According to our previous experience, the authorities usually release the notice on the second day," said a sales manager, surnamed Gu, at Qiangsheng Travel, adding that the trips to Bangkok have not been affected.

A tsunami watch means there is the potential for a tsunami, not that one is imminent.

A powerful 8.6-magnitude earthquake and strong aftershocks struck off Indonesia on Wednesday, sending people as far away as southern India scurrying from buildings and raising fears of a disastrous tsunami as in 2004.

A tsunami watch was issued for countries across the Indian Ocean after a massive earthquake hit waters off Indonesia on Wednesday, triggering widespread panic as residents along coastlines fled to high ground in cars and on the backs of motorcycles.

Some were screamed "God is great" as they poured from their homes. Others, separated from relatives, cried as they ran frantically through the streets.

The US Geological Survey said the 8.6-magnitude quake was centered 3 kilometers beneath the ocean floor around 434 km from Aceh's provincial capital.

The tremor was felt in Singapore, Thailand, Bangladesh, Malaysia and India. High-rise apartments and offices on Malaysia's west coast shook for at least a minute.

The Pacific Tsunami Warning Center in Hawaii said a tsunami watch was in effect for Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, the Maldives and other Indian Ocean islands, Malaysia, Pakistan, Somalia, Oman, Iran, Bangladesh, Kenya, South Africa and Singapore.

Some countries, including Thailand, India and Sri Lanka, lifted their tsunami warning later on Wednesday.

It will not have a disastrous effect on China in the short term, though the situation must be closely monitored, according to a tsunami monitoring report released by the China National Marine Environmental Forecasting Center on Wednesday.

Fu Cifu, a forecaster in the center, warned Chinese tourists and residents in the affected region to stay in safe areas.

Two Shanghai Airlines flights heading from Shanghai Pudong Airport for Phuket Island, off the southwest coast of Thailand, due to take off at 9:15 pm and 20:15 pm, were cancelled immediately. However, the flights heading for Bangkok were about to take off according to schedule.

"We have a tour group setting off on Thursday, but so far we have not received any notice from the Shanghai Municipal Tourism Administrative Commission. According to our previous experience, the authorities usually release the notice on the second day," said a sales manager, surnamed Gu, at Qiangsheng Travel, adding that the trips to Bangkok have not been affected.

A tsunami watch means there is the potential for a tsunami, not that one is imminent.