Three civilians were killed and 22 others injured when suspected Liberation Tigers of Tamil Eelam militants opened fire at a passenger bus in Galge town in south-central Sri Lanka [Images] on Friday.

The incident happened on the Buttala-Katharagama main road in Uva province at 10.15 on Friday morning, officials said.

Those seriously injured were initially rushed to the hospital at Katharagama and later shifted to the base hospital in Hambantota, sources said.

The Tamil Tigers have been fighting since 1983 for an independent state in Sri Lanka's north and east for minority ethnic Tamils, accusing the government of discrimination. The fighting has claimed more than 70,000 lives.

Fighting, which has escalated in the past two years, further flared after the government announced in January that it was pulling out of a tattered ceasefire in Sri Lanka.