BANDA ACEH // Indonesia has issued a fresh tsunami warning after an aftershock with a preliminary magnitude of 8.2 shook its western coast.
The first 8.6-magnitude quake off Aceh province, hours earlier, spawned a wave around 80 centimetres high but caused no serious damage.
The US Geological Survey said the strong tremor that followed was centred 15km beneath the ocean around 615km from the provincial capital, Banda Aceh.
Harjadi, a local official who goes by only one name, said the new tsunami warning was for residents living along the western coast of the country.
It included Sumatra island and the Mentawai islands.
"The aftershock continued for four minutes, and it was strong," an AFP correspondent in Banda Aceh said. "People are panicking and running outside their home and from buildings."
Susilo Bambang Yudhoyono, the Indonesian president, said there was "so far no tsunami threat," after the first shock, but that the country remained on alert.
"So far, there is no report of significant damages and casualties," he added.
India, meanwhile, added the coastal states of Kerala, Orissa, Goa and West Bengal to a tsunami warning along with Andhra Pradesh and Tamil Nadu.
A more urgent "red alert" warning was earlier issued for the Andaman and Nicobar Islands, located in the Indian Ocean.
"We have evacuated a few hundred people. There is no report of any damage so far," Shakti Sinha, chief secretary of Andaman and Nicobar islands, said.
A small tsunami measuring 10 centimetres (four inches) reached Thailand's Andaman Coast.
"A 10cm tsunami wave generated by the first earthquake hit Koh Miang off Phang Nga," the director of Thailand's National Disaster Warning Centre, Somsak Khaosuwan, said on Thai television.