Monsoon rains have caused the worst flooding for 14 years in Sri Lanka where at least 188 people have died and more than half a million have lost their homes.
The southwest of the island has been the worst affected, although heavy rains have triggered landslides and road closures in many areas.
The UK Foreign Office is warning Britons to seek local advice before travelling to affected areas.
One of the worst hit regions is the southern coastal district of Galle, which is popular with foreign tourists, where some villages have not been able to receive essential supplies due to access difficulties.
The army has deployed a dozen aircraft for the evacuation effort and to carry food and other essentials to affected areas.
However, rescue efforts are being hampered by lack of drinking water, lack of electricity and continued rain.
Sri Lanka has appealed for international assistance from the United Nations and neighbouring countries.
