Sri Lanka has canceled all leave for all hospital staff working in coastal hospitals and placed them on high alert, the health ministry said in a statement in Colombo on Wednesday after a tsunami warning.

The government has also disconnected electricity and suspended railway services to coastal areas after issuing a tsunami warning following a massive 8.6 magnitude earthquake off the west coast of Indonesia.

The State Ceylon Electricity Board has disconnected electricity to all coastal areas to prevent breakouts of fire and other disasters following the tsunami warning, according to the Government Information Department.

Railway services to coastal areas have also been stopped to prevent any casualties while private bus services have also been suspended for three hours.

Several areas in the capital as well as the rest of the country felt tremors but no damaged property and causalities have been reported yet, the police said.

Officials of the Disaster Management Center have issued a precautionary tsunami warning asking people in the southern, eastern and Colombo regions of the country to move inland.

Thousands of people walked out of their office buildings and stood outside on the pavement as tremors were felt.

"I was on the seventh floor of my office building when we felt it... Everyone rushed out of the building," said office executive Chaminda Amerasinghe.

Sri Lanka lost around 40 000 people during the last tsunami in 2004.