Suspected Tamil Tiger rebels set off a roadside bomb that wounded three police officers on Saturday, the military said, as government and rebel negotiators prepared for peace talks.
The bombing targeted a group of police officers on a road-clearing patrol in the volatile northern district of Vavuniya, a defence ministry officer said on condition of anonymity because he was not authorized to speak to the media.
Vavuniya is the northernmost government-held garrison town before Tiger-held territory.
The rebels did not immediately comment on the bomb attack. Government and Tiger officials are in Geneva for two-day talks set to start Saturday, aimed at salvaging a 2002 Norwegian-brokered ceasefire that has virtually collapsed amid a major surge in fighting.
The rebels are holding formal talks with a government delegation for the first time since February, when both sides agreed to take "all necessary measures to ensure that there will be no intimidation, acts of violence, abductions or killings."
A second round of talks planned for April was canceled after each side blamed the other for the rising violence.
Increased fighting in the island country off southern India has killed about 2,000 soldiers, rebels and civilians this year.
The rebels want a self-ruled homeland for the country's minority ethnic Tamils, citing discrimination by the majority Sinhalese.
The government says it can offer autonomy, but not a separate state. The civil war flared up in 1983, and 65,000 people were killed until the truce in 2002.