Tamil guerrillas staged attacks across Sri Lanka yesterday, assaulting a Navy camp and setting off bombs in two buses and a rickshaw, government and rebel reports said. At least 43 persons died and 124 others were injured.

Tamil separatists, fighting for a separate homeland in the island nation, detonated time bombs in two buses as they passed near a military base in the eastern port city of Trincomalee, 150 miles northwest of Colombo, the government said. Each bus was carrying about 75 persons, it said.

Col. Lucky Wijeratne, military coordinating officer for Trincomalee district, told United Press International that at least 18 persons were killed and 68 were injured on the buses.

The Press Trust of India news agency, monitored in New Delhi, quoted rebel sources as saying a Tamil mortar attack on a naval camp in northern Sri Lanka killed 19 Navy personnel.

A bomb in a motorized rickshaw outside a movie theater in the Kotahena section of Colombo exploded as the crowd was leaving, injuring 36, police said. The driver of the rickshaw was arrested, but an accomplice fled.

In addition to the rebel attacks, six Tamil guerrillas also were killed and 20 were seriously injured in operations by security forces around the island, the rebels quoted by the Press Trust of India said.