COLOMBO (AFP) -- The tottering peace process in Sri Lanka suffered fresh blows after a week of mine attacks blamed on Tamil Tiger rebels, officials and diplomats said Sunday.

The rebel Liberation Tigers of Tamil Eelam (LTTE) escalated their attacks as they were not serious about attending talks in Switzerland on saving their troubled ceasefire, a top government official said.

Palitha Kohona, the head of Colombo's peace secretariat, said the guerrillas were trying to stay away from the Swiss talks rescheduled for April 24-25 by pushing back the original date by five days. "I believe the ball is now in their court," Kohona told AFP. "We are doing everything to go to Geneva for the talks but we can't clap with one hand. There must be commitment by both sides."

For their part, the Tigers accused Sri Lanka's navy of scuttling preparations for the talks by "excessive interference" in the transport of rebel field commanders between the east and the north of the island Saturday.

The Tigers had said they wanted internal consultations among field commanders before the talks and that the navy had imposed conditions on their transport arrangements.

The Tigers called off their planned movement of some 32 senior cadres and raised doubts about the Geneva meeting but have stopped short of pulling out of the talks, which have been trimmed to two days instead of three.

"We wish to emphasise today's incident has put into question our decision and subsequent efforts to go to Geneva," the LTTE's political wing leader S. P. Thamilselvan said in a letter to the Norwegian peace brokers Saturday.

"We strongly suspect the latest act of the government of Sri Lanka is aimed at worsening the situation by rejecting the goodwill measures already in existence since the signing of the ceasefire," the letter said.

Diplomats involved in the peace process said the latest stand-off could lead to more violence in the island's troubled regions where 55 people, mostly security personnel, were killed in mine attacks in the past week alone. "We are going down a slippery slope," a diplomatic source said. "The two parties can still make a commitment to uphold the ceasefire and they have the power to put an end to the violence."

Four previous peace efforts had ended in failure in a country where over 60,000 people have been killed in three decades of ethnic bloodshed between the majority Sinhalese and minority Tamils.

The Swiss talks on saving a shaky February 2002 ceasefire have already been postponed once at the request of the LTTE.

On Thursday, Norway won agreement from both sides for a five-day delay to allow the Tigers more time to prepare for the discussions that would be a continuation of a round held in February.

Both sides have accused each other of failing to deliver on pledges to bring an end to the violence.