Only two British deaths have so far been definitely confirmed - one in Thailand and one in the Maldives.
But the overall death toll continues to climb, with the latest count clocking as many as 14,000 lives lost after the series of floods swamped much of Asia following a magnitude 9.0 earthquake off Indonesia's coast yesterday.
Aftershocks were felt as far away as Somalia, on Africa's eastern coast.
There were reports of tourists and divers being swept away as they bathed in the popular resort of Phuket, in Thailand. British relief teams are heading to the quake zone.
The quake epicentre was off the western island of Sumatra, Indonesia, where nearly 4,500 people were killed.
It struck at about 1am GMT (8am local time) initially destroying dozens of buildings before a huge wall of water, more than 30 ft high in places, hit the provinces of Aceh and North Sumatra.
Officials said Aceh was the worst hit area, which lies closest to the epicentre. Coastal towns and villages, and the resort island of Nias, were flooded.
But the highest death toll so far has been in Sri Lanka where at least 6,090 lives were lost - 4,590 reported dead in government-controlled areas and at least 1,500 dead in Tamil rebel-controlled territory.
A wide stretch of the eastern coastline - from Jaffna in the north to the popular tourist beaches in the south - has been devastated. Waves as high as 20ft hit several districts.
More than a million people have been forced from their homes, according to officials. The port in the capital, Colombo, was shut by flash floods.
In India 2,283 are dead after 1,243 miles of southern coast was swamped by tidal waves, including the states of Tamil Nadu - whose capital, Madras, was particularly badly hit - Andhra Pradesh, and Kerala, as well as the federally administered territory of Pondicherry.
Hundreds of fishermen are missing off the southern coast, and there are reports of scores of bodies being washed up on beaches.
A nuclear reactor in Tamil Nadu was shut down after sea water entered an estate housing scientists.
Heavy damage is also reported in the Andaman and Nicobar islands. Jetties on the island's main port have collapsed and many people have been forced out of their homes.
In Thailand 431 people were killed. The popular British tourist resorts of Phuket and Phi Phi islands and the mainland resorts of Krabi and Phang Nga, on the western coast of southern Thailand, were badly hit.
Reports say divers and sunbathers were swept out to sea from beaches near Phuket.
In neighbouring Malaysia 48 were killed after people were swept away from beaches near the northern island of Penang. The mainland states of Kedah and Perak were also affected.
High waves and floods inundated the Maldives islands killing 32 people. The British man killed was a victim of flooding and was thought to have suffered a heart attack as the tidal wave struck.
Large areas of the capital have been left under water and some low lying islands abandoned. Some of the country's 200 islands cannot be contacted.
Quake deaths were also reported in Myanmar (12) after the south-eastern coast was struck by a huge wave; in Bangladesh (2) and Somalia (9), in Africa.
The northern Somali coastline, more than 3,728 miles from the epicentre, was reported affected.
There are unconfirmed reports of fatalities in Kabaal in the north-east and in Elmaan, north of the capital, Mogadishu.
Waves also struck Kenya, after hitting Mauritius, Reunion and the Seychelles on the way.
The Foreign Office has set up a phone number - 0207 008 0000 - for those worried about friends and relatives.
sophie.hazan@ypn.co.uk