BANGKOK, Thailand - The extraordinary loss of life from Sunday's earthquake and tsunamis is prompting Asian governments to consider developing a more comprehensive and effective warning system.

Scientists nearest the quake's epicenter knew shock waves could create tidal surges that would threaten coastal regions and shipping, but said Monday they had no way of measuring the size of the danger because a warning network like one used in the Pacific is not installed in the Indian Ocean.

The technology might have saved countless lives Sunday by giving residents in coastal areas - especially in Sri Lanka and India, the hardest-hit nations hundreds of miles from the quake - time to flee to higher ground.

Officials in Thailand issued the only warnings of the impending disaster, but broadcasts beamed to tourist resorts in the country's south underestimated the threat and a Web site caution was not posted until three hours after the first waves hit.

Residents in Sri Lanka, where thousands were swept away or drowned, expressed disbelief that a warning system was in place elsewhere in the world but not in the Indian Ocean.

"This is tragic," said retired Sri Lankan air force chief Harry Goonetilleke. "There should have been such an arrangement for the region. This is absolutely not acceptable."

U.N. Undersecretary-General for Humanitarian Affairs Jan Egeland, who is also the U.N. emergency relief coordinator, said he was not aware the region didn't have a warning system.

He said the World Conference on Disaster Reduction next month in Kobe, Japan, will now consider whether such a system can be designed and whether it is even possible to evacuate such large coastlines with only a few hours' notice.

"This is something we have to look into. I think it would be a massive undertaking to actually have a full-fledged tsunami warning system that would really be effective in many of these places," Egeland said.

India's information minister, Dayanidhi Maran, said his country would consider setting up a warning system, and Australian Prime Minister John Howard said he would investigate what role his country could play in the effort. Japan's government also indicated it would lend expertise developed from the Pacific alert system that was started nearly 40 years ago.

The head of the Commonwealth, the bloc of Britain and its former colonies, called for talks on creating a global early warning system for tsunamis.

The magnitude 9.0 earthquake - the world's most powerful since 1964 - shifted huge geological plates beneath the ocean northwest of Indonesia's Sumatra island an hour or two after daybreak, causing a sudden displacement of millions of tons of water.

Indonesian villages closest to the temblor's epicenter were swamped within minutes, but waves also radiated outward, gathering speed and ferocity until they made landfall.

Waves began pummeling southern Thailand about an hour after the earthquake. After 2½ hours, the torrents had traveled some 1,000 miles and slammed into India and Sri Lanka.