By Helen Murphy
BOGOTA (Reuters) - Colombia's government warned on Tuesday of a plot by a criminal group to kill several high-profile journalists just weeks after the attempted assassination of an investigative reporter boosted concerns over threats to a free press in the violence-plagued Andean nation.
President Juan Manuel Santos also announced that 90 journalists are being given protection by the government. He urged Attorney General Eduardo Montealegre to investigate attacks against journalists.
"In this government, we're totally committed to get to the very bottom of the problems that undermine this fundamental right to be well-informed that all Colombians have," Santos said at an event to promote media rights.
Journalists and investigators have long been the target of attacks and threats in Colombia, allegedly carried out by corrupt politicians, drug lords, Marxist rebels and right-wing paramilitary leaders to silence coverage that may damage their interests.
A hit man has entered the Colombian capital to kill columnist Leon Valencia, analyst Ariel Avila and reporter Gonzalo Guillen, according to Andres Villamizar, head of a government-run agency to protect high-profile targets.
"We won't allow these plans to be carried out," Villamizar said early on Tuesday on his Twitter account, pledging to step up security.
Before entering politics, Santos served as an editor at the country's top newspaper, El Tiempo, once owned by his family. He said he will strive to protect freedom of expression "because that's where I was born, it's at the heart of who I am."
Even though a U.S.-backed military offensive has improved security in Colombia over the last decade, the new threats throw a spotlight once again on the dangers for reporters covering corruption and criminal gangs in Colombia. This comes as the government seeks a peace accord with the biggest rebel group, the FARC.
The threat likely stems from an investigation into links between paramilitary groups and politicians during last year's municipal elections, Valencia, a former Marxist rebel and columnist for the respected Semana magazine, told Reuters.
The hit man was probably hired by a criminal group with links to politicians, Valencia said.
"No doubt we're afraid because the people involved are very powerful and have no limits," Valencia said. "We will continue investigating, nothing will stop us."
Paramilitary groups continue to operate across Colombia even after former President Alvaro Uribe negotiated their demobilization in 2008 and many handed in their weapons in exchange for light jail sentences. Thousands have morphed into new drug-funded crime gangs and continue to kill and make threats if their operations are at risk.
It was not immediately clear why Guillen would be targeted alongside Valencia and Avila.
Colombia has been rattled by a five-decade war involving various insurgent groups - including the Revolutionary Armed Forces of Colombia, or FARC, and paramilitary forces - that has killed more than 100,000 people and forced millions to flee their homes.
The new generation of criminal gangs is now fighting with the FARC and paramilitary groups for control of drug-smuggling routes and illegal activities, while journalists, union workers and residents are often caught in the middle.
The latest threat comes on the heels of an assassination attempt two weeks ago on Ricardo Calderon, an investigative journalist who narrowly survived an ambush that riddled his car with bullets as he returned to Bogota after reporting on irregularities in a military prison for Semana magazine.
Last week, eight journalists were given 24 hours to leave the city of Valledupar, in Cesar province, as they reported on government attempts to return stolen land to war victims. Leaflets from a little-known group, the Anti-land Restitution Army, declared the reporters collaborators and hence targets for death.
All the reporters and analysts threatened have worked on some of the most damning stories, including corruption in northern La Guajira province, the government's intelligence agency wire tapping opponents, and right-wing paramilitary involvement in the nation's Congress.
(Additional reporting by Luis Jaime Acosta and Eduardo Garcia in Bogota; Editing by Vicki Allen and Will Dunham)