A Colombian broadcast reporter at work on a report about the country's murderous right-wing paramilitaries received a threatening telephone call last week, Reporters Without Borders said Monday.

The threat took the form of a three-minute call featuring the sound of automatic weapons fire over a musical background, the Paris-based group, known as RSF, said in a statement.

Paul Bacares, who works with the public television station Bogota Canal Capital, is preparing a report on paramilitary activity in the central province of Boyaca, RSF said.

"The paramilitaries, the most likely authors of this 'warning,' are still the biggest source of danger for Colombia's journalists, often treating them as 'military targets,'" the statement continued.

"Bacares must quickly be given protection that is appropriate to the nature of this threat. The authorities should also examine the security needs of his Canal Capital colleagues, who could be exposed to the same danger," RSF insisted.

The press freedom watchdog suggested Bacares was threatened because he has been investigating paramilitary infiltration of the legal economy in Boyaca and the gunmen's ties to politicians and other notables.

If Bacares' report is not broadcast, RSF said it will make the piece available on a soon-to-be-created censorship circumvention Web site.

Colombia's right-wing militias have killed more than 250,000 people since the mid-1980s, according to a U.S. State Department cable disseminated by WikiLeaks. EFE