Sri Lankan officials say a sea battle with Tamil rebels will have no impact on the government's plans for an indefinite ceasefire. Government and rebel sources say they expect a permanent ceasefire agreement to be announced Friday.

Sri Lankan defense officials say the sea battle took place just off the coastal town of Mullaitivu - a major rebel base about 200 kilometers northeast of Colombo. The officials say navy ships spotted about a dozen rebel boats, triggering the fighting between the two sides.

Constitutional Affairs Minister G.L. Peiris said the incident will not derail plans to put a permanent cease-fire with the rebels into effect.

Both the rebels and the Sri Lankan government are observing separate unilateral cease-fires that are due to expire Sunday.

Norwegian mediators have been trying to reach agreement on a permanent truce before the current ceasefires end. The new agreement is expected to pave the way for peace talks with the rebels.

Hopes of starting talks with the Tamil rebels rose when a new government took charge in December, pledging to end the Tamil separatist conflict through negotiations. All previous attempts to begin talks have broken down.

The government has already taken several steps to encourage the rebels to enter peace talks. It has eased an economic blockade of rebel-held areas in an effort to improve living conditions of Tamil civilians and a main highway that runs through rebel-controlled territory was also reopened last week for the first time since 1996.

The Tamil separatist insurgency has raged in the north and east of Sri Lanka since 1983, and claimed more than 60,000 lives. Tamil rebels complain of discrimination against their minority community and say they want a separate homeland.