One Sri Lankan soldier was killed and six policemen wounded in attacks on Saturday blamed on Tamil Tiger rebels as government negotiators opened peace talks with the insurgents in Geneva.
At least six police officers were wounded, one critically, in two separate Claymore mine attacks in the island's north and east, defence officials said.
In another attack in the east, one soldier was killed when suspected Tiger guerrillas ambushed his patrol, the government said.
Police in the capital Colombo stepped up security, erecting roadblocks and searching each vehicle entering the city.
Checkpoints created long queues of cars and trucks, bringing traffic to a halt.
The talks in Geneva between the government and the Liberation Tigers of Tamil Eelam are aimed at halting months of bloodshed and reviving a tattered 2002 truce agreement.