MADHU, SRI LANKA, JUNE 16 -- The government of this beleaguered island nation announced a cease-fire agreement tonight with ethnic Tamil separatist guerrillas. But in this northern province, where hundreds are estimated to have died in fighting this week, there were few signs of imminent peace.

The government announced the truce and an agreement to exchange prisoners following two days of talks in the northern city of Jaffna with leaders of the Liberation Tigers of Tamil Eelam, whose guerrillas this week broke a month-long truce by attacking army and police posts and taking hundreds of Sri Lankan policemen prisoner throughout the north and east.

But there was no public endorsement of the cease-fire by the Tamil Tigers, and tonight guerrillas manning roadblocks and defending camps in this northern jungle said they had received no word from their leadership about whether to abide by it. "We have heard the news, but so far we have received no instructions by radio," said one Tigers commander an hour after the cease-fire was supposed to have been in effect.

Battles for control of northern road junctions, police stations and army camps continued today, and tensions remained high on both sides. Sri Lankan officers and soldiers, who have been confined to their northern and eastern camps for months as part of an attempt by President Ranasinghe Premadasa to negotiate a settlement, said they were anxious to continue their fight against the guerrillas in the hope that the Colombo government would emerge victorious once and for all.

"We don't like it when the government talks" with the Tamil Tigers, said one army sergeant who said he was sleepless from four days of battle with the guerrillas for control of the northern city of Vavuniya. "We are ready to fight. There is a big war going on."

Heavily armed guerrillas, some no older than 15, patrolled roads and occasionally attacked army convoys moving reinforcements to the north today.

To counter the guerrillas, Sri Lankan government officials distributed rifles and ammunition to Sinhalese civilians in the region who could be expected to fight against the minority Tamil rebels. The distribution of weapons to civilians was apparently unprecedented in Sri Lanka's recent history of ethnic and civil strife.

"The village people are frightened and have moved out of their homes because they don't have any security if an emergency comes," said Nisanka Dissayake, a member of parliament who was distributing government weapons near here today. "I'm just going to give them rifles for protection."

Most of the island's north and east is dominated by ethnic Tamils, but there are also large areas of mixed Tamil, Sinhalese and Moslem populations. There have been incidents of civilian ethnic battles in such regions during the fighting this week.

In a village 10 miles from here on Friday, a Sinhalese mob burned to death a local Tamil schoolmaster hours after guerrillas ambushed a Sri Lankan army convoy, killing five soldiers, according to witnesses. So far, however, there have been no reported outbreaks of large-scale ethnic rioting.

The question hanging over this war-ravaged region is whether after a week of fierce fighting and high tension, the guerrillas and the Sri Lankan army can be persuaded to return to their bases while leaders in Colombo and Jaffna try to stitch back together the fragile political settlement that had brought rare peace to Sri Lanka in recent months.

The government said the agreed prisoner exchange is to include the release of an estimated 700 Sri Lankan policemen captured by the guerrillas when they overran police stations in the north and east. There have been unconfirmed reports that a large number of policemen have been executed by the Tamil Tigers, a charge the guerrillas have denied.

During the truce that fell apart this week, the government and the Tamil Tigers were trying to negotiate a plan to give political autonomy in the north and east to the Tamils, who are dominated militarily and politically by the Tigers. But the talks have stagnated recently because the Tigers have refused to surrender their weapons in anticipation of elections and because the government has been slow to deliver on some of its assurances.

The Tigers, who have effectively taken over the civil government of the north and east, are estimated to have a fighting force of between 5,000 and 15,000 guerrillas, many of them young Tamils recruited recently after the final withdrawal of Indian troops from the island in March. The Sri Lankan army is estimated to have between 35,000 and 50,000 troups, roughly the same number as the Indian peacekeeping force, which was defeated by the Tigers during almost three years of jungle fighting.