Landmine blasts in Sri Lanka killed two sailors Thursday and wounded two government commandos in the north of the country.

The two sailors were riding a motorcycle in the government-held enclave of Jaffna when an antipersonnel mine exploded, mortally wounding them. The commandos were wounded in a separate attack near Sri Lanka's northwest coast. Officials blame both attacks on Tamil rebels.

Earlier Thursday, government forces said they had ended a two-day offensive against rebel positions around Trincomalee, the large port on Sri Lanka's northeast coast. Thousands of people fled their homes to escape the air strikes - the first major military action by the government since a 2002 cease-fire.

Tamil rebels say more than 40,000 people in Trincomalee district were forced to leave their homes. Workers for the U.N. refugee agency say it is clear there are a large number of refugees, but they could not confirm the Tamil rebels' estimate.

The rebels say the government's offensive spread terror through the Tamil community this week. They are asking the international community to condemn Colombo's tactics.

The army says it reopened road access Thursday between southern Sri Lanka and rebel-held territory in the north. The government had closed the highways after Tuesday's deadly suicide bombing in Colombo, blamed on the rebels.

European truce monitors say a 2002 cease-fire agreement between the government and the Tamil rebels still holds. But one European official Helen Olafsdottir warned Sri Lanka will plunge back into civil war if the violence is not stopped immediately.