The council of Engineers warned yesterday that new buildings in Greater Bangkok had to be made earthquake-resistant.
Last week saw a 4.6-magnitude undersea quake and another of similar power near Koh Yao district in Phang Nga province, but no injury or serious damage was reported.
Amorn Pimanmas, deputy chief of the council, said buildings in the capital and its suburbs, which sat on a soft layer of soil, should have ferro-concrete beams to support structures.
The west fault line and the Myanmar fault line could trigger an earthquake that could strike Bangkok if it were stronger than magnitude 8, he said.
Kornravee Sitthichvapak, director of the Seismological Bureau, said Thailand had 14 fault lines. Bangkok is one of the at-risk areas that could face a magnitude 6 tremor.
The Ranong Disaster Prevention and Mitigation office has drawn up an emergency plan to deal with severe seismic phenomena.