The men were murdered Saturday in two separate incidents on the government-controlled peninsula, situated at the northern tip of Sri Lanka but cut off from the rest of the island by Liberation Tigers of Tamil Eelam (LTTE) territory.
"The two civilians were shot dead by the suspected LTTE assassins in separate incidents in the Jaffna peninsula during the last 24 hours," the defence ministry in Colombo said.
The pro-rebel Tamilnet.com website, however, said it was the work of military intelligence operatives.
"Informed Jaffna sources said that the terror campaign has been stepped up by military intelligence operatives following a Claymore attack in Navanthurai where a military intelligence official was reportedly killed," Tamilnet said.
Amnesty International has reported that during the past year more than 1,000 people are believed to have been "disappeared" and the same number had been unlawfully killed across the island.
Sri Lanka's government has come under increasing pressure o