Sri Lanka's Tamil Tiger rebels must let opposing ethnic Tamil politicians campaign freely for an April election and all parties must work to keep the poll peaceful, Amnesty International said on Saturday.
The rights watchdog said there had been more than 100 reports of election-related violence, most involving the rival parties of Prime Minister Ranil Wickremesinghe and President Chandrika Kumaratunga, front-runners in the April 2 vote, but Amnesty said it was also concerned about Tamil parties.
"We are particularly concerned that candidates and supporters of Tamil political parties not allied to the Tamil National Alliance (TNA) - which the LTTE is backing in elections - may become targets for assassination," Amnesty said in a statement.
The Liberation Tigers of Tamil Eelam (LTTE) rebels began their war for a separate state for minority Tamils in the island's north and east in 1993 but they and government forces have been observing a cease-fire since February 2002.
Despite the truce, the United States said in a recent report the rebels had killed more than 36 members of Tamil political groups in the past year.
The Tigers will not field candidates in the election but have endorsed the TNA, which could play a kingmaker role in what looks set to be a tight race.
The endorsement was the first by the rebels, who have increasingly been using proxies to fight political battles since the Norwegian-brokered truce was signed.
The Tigers were to meet Nordic monitors who oversee the cease-fire on Saturday to discuss maintaining the peace during the campaign and how monitors can help voters get from rebel territory to polling stations in areas under government control.
The election will be fought mainly over how to pursue peace with the rebels, with Kumaratunga's party saying Wickremesinghe conceded too much to the Tigers in the six rounds of talks his government presided over.