BANDA ACEH, Indonesia - A major earthquake struck off the west coast of Indonesia's Sumatra Island late Monday, and officials issued a tsunami warning for as far away as Sri Lanka. Residents of Banda Aceh fled their homes in panic.
The U.S. Geological Survey said the temblor, which occurred at 11:09 p.m. local time (11:09 a.m. EST), measured a magnitude of 8.2. It was described by one of the agency's geologists as an aftershock of the devastating Dec. 26 quake.
In Banda Aceh, the Sumatran city that was hit hardest by December's tsunami, the quake cut electricity and thousands poured into the streets, most getting into vehicles to flee low-lying areas.
Tsunami warnings were issued in Thailand, Japan and Sri Lanka. Authorities said it could take several hours to know whether the quake had generated a devastating tsunami.
Sirens blared along Sri Lanka's devastated east coast as the government warned seaside residents to evacuate immediately.
"The government has ordered coastal areas to move to higher ground. We are giving priorities to eastern coast," said Brig. Daya Ratnayake, the military spokesman.
Low-lying coastal areas in Malaysia's northern states also were being evacuated.
In Washington, State Department deputy spokesman Adam Ereli said U.S. diplomatic missions in Asia and Africa are in "battle mode" so that they can respond quickly to any contingency.
He said embassy officials in the area have been asking host governments to inquire about any causalities to permit an early U.S. response if the situation calls for it.
The International Red Cross in Geneva said all their mobile phone systems were down so they haven't been able to talk to anyone on the ground in Indonesia.
At the Office for the Coordination of Humanitarian Affairs, which was at the center of U.N. response to the Dec. 26 tsunami, Jamie McGoldrick said, "What's going on is a mobilization of people away from the coast."
But noted that the quake was "a weaker one than before (Dec. 26)."
Oceanographer David Burwell of the Pacific Tsunami Warning Center in Hawaii said the agency was watching water levels "but we don't have any gauges in that area." He said it would be a few hours before officials received any readings.
The quake lasted for about two minutes - far longer than most of the daily aftershocks that have rocked Aceh since Dec. 26.
"People are still traumatized, still scared, they are running for higher ground," said Feri, a 24-year-old recovery volunteer who goes by one name.
"It was felt in most of the cities in Sumatra," said Budi Waluyo, an agency official. Indonesia's state news agency, Antara, said there were no immediate reports of damage.
The quake was felt as far away as Malaysia, about 300 miles from the epicenter, sending panicked residents fleeing their apartments and hotels in Kuala Lumpur and Penang after authorities activated fire alarms.
Officials issued a tsunami warning for residents of southern Thai provinces, three months after a tsunami devastated parts of Indonesia and other countries in the region.
The quake occurred at a depth of 18.6 miles, and was centered 125 west-northwest of Sibolga, Sumatra, and 150 miles southwest of Medan, Sumatra, the USGS said.
After the Dec. 26 quake, the agency initially recorded the depth of that temblor at six miles. Shallow earthquakes like that generally are more destructive because the seismic energy is closer to the surface and has less distance to travel.
Monday's quake was considered to be at a moderate depth.
Japan's Meteorological Agency said the quake registered 8.5.
Tremors also were felt throughout peninsular Malaysia's west coast, causing thousands of residents to flee high-rise apartment buildings and hotels. There were no immediate reports of any casualties or major damage.
"I was getting ready for bed, and suddenly, the room started shaking," said Kuala Lumpur resident Jessie Chong. "I thought I was hallucinating at first, but then I heard my neighbors screaming and running out."
Police were evacuating many residents from low-lying coastal areas in Malaysia's northern states of Penang and Kedah as a precaution, said Penang Police Chief Christopher Wan.
"We are on the alert for the possibility of a tsunami within the next few hours," Wan said by telephone. "We're better prepared now compared to last year."
Sixty-eight Malaysians were killed when the Dec. 26 tsunami hit Penang and Kedah.
Greg Romano, spokesman for the National Oceanic and Atmospheric Administration, which operates the Pacific Tsunami Warning system, said the U.S. State Department was passing on warnings to foreign governments about the tsunami danger.
The USGS said the quake occurred on a segment of the same fault line that triggered the magnitude-9 earthquake on Dec. 26, the world's biggest in 40 years.
Dale Grant of U.S. Geological Survey said the quake was magnitude 8.2 and was in the aftershock zone of the Dec. 26 quake.
"It is along the same segment of fault," he said. "We do expect aftershocks. An 8.2 is very large, but it's not unusual as an aftershock."
He stressed they have no reports at this time of any tsunami.
The Dec. 26 quake triggered the huge tsunami that swept across the Indian Ocean at the speed of a passenger jet killed more than 174,000 people and left another 106,000 missing.
More than 1.5 million people were left homeless in 11 countries..
Tremors form the quake could be felt in the Thai capital Bangkok for several minutes beginning at about 11:20 p.m.
Chalermchai Aekkantrong, deputy director of Thailand's meteorological department, told a radio station Monday that officials were asking people near the coast to evacuate, although there were no immediate reports of a tsunami.
