The military launched air attacks on July 26 to pressure the Tigers to open the waterway. The guerrillas resisted and said residents closed the waterway to get the government to improve drinking water supply to them.

‘‘Our objective of the mission with a defensive character was accomplished and our forces returned to their positions as per the February 2002 ceasefire,’’ LTTE military spokesman I Ilanthiayan was quoted as saying by Tamilnet.com website.

He said 32 Tigers were killed during the fighting, far lower than the 152 rebel fatalities claimed by the Defence Ministry in clashes in and around Muttur late Friday alone.

The Defence Ministry said on Saturday Tiger rebels massacred at least 100 refugees in northeastern Sri Lanka, raising to 426 the number of people killed in 11 days of violence. A Ministry statement said the LTTE blocked civilians, mainly Muslims, fleeing the town of Muttur and killed at least 100 of them on Friday night.

There was no immediate reaction from the Tigers to the claim which came as Muslim legislators accused the guerrillas of holding over 100 Muslim civilians who had tried to escape the fighting in Muttur.

The International Committee of the Red Cross (ICRC) said they had no access to the area and could not verify claims of civilian casualties or if people had been massacred.

‘‘We still have no access to the area and therefore we can’t say anything about these reports (of civilian losses),’’ ICRC spokesman Sukumar Rockwood told AFP.

Earlier in the day, the Defence Ministry here said security forces had killed another 152 Tiger rebels in a major air, land and sea offensive in the northeastern town of Muttur on Thursday evening.

The reports of the latest fatalities came as Oslo’s special envoy, Jon Hanssen-Bauer, travelled to the rebel-held town of Kilinochchi for what diplomats said were desperate talks to restore the collapsing ceasefire. Bauer, who held talks with Sri Lankan PM Ratnasiri Wickremanayake on Friday, is expected to spend the weekend in rebel-held territory.

-Amal Jayasinghe