"Take part in evacuation drills and ensure that your houses are as strong as possible," said NDWC chairman Smith Dharmmasaroj.

Smith confirmed that the Mae Chan fault in Thailand had been more active since the Boxing Day 2004 earthquake off of Sumatra.

Movement on the Mae Chan fault caused the powerful quake on the Lao-Burmese border on Wednesday afternoon.

Measuring 6.3 on the US Geological Survey's instruments, the quake caused tremors that were felt far away in Bangkok.

In Chiang Rai, less than 100 kilometres from the quake's epicentre, buildings suffered cracks, and the top of an ancient pagoda's tiered umbrella collapsed.

At press time, officials were still scouring the pagoda compound in search of five missing gems that disappeared during the collapse. They were among nine jewels embedded into the top of the Chomkitti Pagoda's umbrella. Their Majesties the King and the Queen had graciously donated the gems during the pagoda's renovation three decades ago. "We'll search until we find all of the gems," said Chiang Rai governor Amornphan Nimanan.

He said relevant officials were now surveying the damage to local residences. At least 60 homes had suffered some damage.

Suwit Busarakul, director of Ban Pong Phrabat School in Chiang Rai's Muang district, said cracks had appeared in the school's classrooms and that lessons were being conducted in the school's library instead.

Meteorological Department director-general Suparerk Tansriratanawong said his department was planning to open 30 more earthquake-measuring stations by the end of the year. There are now only 15 such stations in the Kingdom.

"If earthquakes occur, we plan to alert people within five minutes through mass media like television and radio," he said.

Suparerk urged people to stay as far away as possible from glass or lamps during an earthquake. "Do not rush out of buildings. Wait until the vibration stops before you evacuate," he added.

Mineral Resources Department director-general Apichai Chawacharoenpan advised people to take shelter behind structures and beware of items that could fall on them.

"Residents of high-rise condominiums should keep torches handy," he said.

Information and Communica-tions Technology Minister Sitthichai Pookaiyaudom said his ministry was in the process of procuring 1,000 early-warning towers at a cost of Bt388 million.

"We plan to install all of them within six months," he said. They would be installed along the coastline and in the North.

Thirawat Kullawanich, director-general of the Public Works and Town and Country Planning Department, said he would ask educational institutes to offer design courses for quakeproof structures to engineering students.