JAKARTA/ KARACHI: An 8.7 magnitude earthquake struck off the coast of Indonesia on Wednesday, sending residents around the region dashing out of their homes and offices in fear.
US seismologists issued an Indian Ocean-wide tsunami watch but said it appeared to have only generated small waves. Victor Sardina, a geophysicist with the US Pacific Tsunami Warning Center in Hawaii, told AFP the first tsunami was "not anywhere near" as large as the devastating waves that struck Asia in 2004 and Japan last year.
He said the tsunami measured a mere 35 centimeters (14 inches) near Padang, Indonesia, but could swell to as high as a meter (3 feet 4 inches) near Sri Lanka, adding that US scientists were still carefully monitoring the situation.
At least three tsunamis of up to 80 centimetres (31 inches) hit Indonesia's coast after a massive 8.6-magnitude earthquake struck off Sumatra island Wednesday.
"Our tide gauges and buoys recorded small tsunamis," Said Kristiawan of Indonesia's Meteorology and Geophysics Agency said.
He said the highest was in Meulaboh in western Aceh, "measuring 80 centimetres", and other smaller ones were recorded in nearby coastal regions.
All were recorded at 10:04 GMT, almost an hour and a half after the initial quake, he said. A strong 8.2-magnitude aftershock struck off Sumatra island at 10:43 GMT.
Earlier, the center said "earthquakes of this size have the potential to generate a widespread destructive tsunami."
The Pacific Tsunami Warning Center in a bulletin after the quake added that "sea level readings indicate a tsunami was generated. It may already have been destructive along some coasts."
"Based on these data the threat continues for all coastal areas of the Indian Ocean," the Hawaii based center said.
The Pacific Tsunami Warning Center said a tsunami watch was also in effect for India, Sri Lanka, Bangladesh, Pakistan, Indonesia, Malaysia, South Africa and other countries.
A tsunami watch has been issued for countries across the Indian Ocean, including Pakistan after a massive earthquake hit waters off Indonesia, a Met department official told The Express Tribune, adding that there was no tsunami threat to Pakistan’s coastline.
People near the coast in six Thai provinces were ordered to higher ground.
Indonesia's president said there were no reports of casualties or damage from the earthquake, with no threat from a tsunami although an alert for a giant wave remained in place.
"There is no tsunami threat although we are on alert," said President Susilo Bambang Yudhoyono at a joint news conference with visting British Prime Minister David Cameron, who said Britain was standing ready to help if needed.
"The situation in Aceh is under control, there's a little bit of panic but people can go to higher ground," Yudhoyono said, adding that he had ordered a disaster relief team to fly to Aceh.
The quake struck 308 miles (500 km) southwest of the city of Banda Aceh, on the northern tip of Indonesia's Sumatra Island, at a depth of 20.5 miles (33 km), the U.S. Geological survey said.
Indonesia's disaster management agency said power was down in Aceh province and people were gathering on high ground as sirens warned of the danger.
"The electricity is down, there are traffic jams to access higher ground. Sirens and Koran recitals from mosques are everywhere," said Sutopo, spokesman for the agency.
The quake was felt as far away as the Thai capital, Bangkok, and in southern India, residents said.
Hundreds of office workers in the Indian city of Bangalore left their buildings while the Indian port of Chennai closed down because of the danger of a tsunami, the port said.
The quake was in roughly in the same area as a Dec. 26, 2004, quake of 9.1 magnitude, which sent huge tsunami waves crashing into Sumatra, where 170,000 people were killed, and across the Indian Ocean.
In all, the 2004 tsunami killed about 230,000 people in 13 Indian Ocean countries, including Thailand, Sri Lanka and India.
The 2004 quake was at a depth of 18 miles (30 km) along a fault line running under the Indian Ocean, off western Indonesia and up into the Bay of Bengal.
One expert told the BBC the Wednesday quake as a "strike-slip" fault, meaning a more horizontal shift of the ground under the sea as opposed to a sudden vertical shift, and less risk of a large displacement of water triggering a tsunami.
The quake was also felt in Sri Lanka, where office workers in the capital, Colombo, fled their offices, and the southern Thai holiday island of Phuket, both of which were hit hard by the 2004 tsunami.
In Bangladesh, where two tremors were felt, authorities said there appeared to be no threat of a tsunami. Australia also said there was no threat of a tsunami there.