Sri Lanka’s air force said it bombed a Tamil Tiger rebel naval base in the country’s north-west today, but a guerrilla spokesman claimed the air raid killed 15 civilians in a fishing village.

Twelve Tamil rebels and five Sri Lankan sailors were killed today in a clash near a western naval base, a navy spokesman said – the latest violence threatening to cause a four-year ceasefire to completely collapse.

Tamil Tiger rebels have claimed responsibility for an attack on a fuel-laden ship that left seven people dead and raised questions about Sri Lanka's maritime safety.