By Helen Murphy
BOGOTA (Reuters) - Colombia's FARC rebels offered armed support to a rural protest in the Andean nation's volatile northeast - a gesture that could ignite violence and increase friction as the Marxist group seeks a negotiated peace with the government.
Their endorsement of the farmers' protest comes at a time when the rebels' relationship with the government already is jeopardized by weekend violence that killed 19 soldiers.
Impoverished farmers in Catatumbo have blocked roads and clashed with police in the past month to protest the government's regular fumigation of illegal coca crops, the only means of subsistence for many, and a lack of state presence.
The confrontations have resulted in the deaths of four protesters and injuries to dozens of people, including police officials who were maimed by explosives.
"They can count on our ranks, on our weapons, on our fighters," the FARC, or the Revolutionary Armed Forces of Colombia, said on Monday in a statement referring to the farmers. "We are ready to receive them, to support them and guide them to final victory."
The FARC is strong in Catatumbo, an area that borders Venezuela and where the state oil company Ecopetrol has operations. But with little employment outside the farming of coca - the raw material that makes cocaine - the FARC has become more empowered over the years and to many is the de facto government.
The second-biggest rebel group, the National Liberation Army, and criminal bands also operate in the area.
The interior ministry "rejected categorically" the FARC's offer of aiding the protest with weapons, while Defense Minister Juan Carlos Pinzon called the proposal "clown-like" and another example of the group's intention to "create disorder."
"It should be clear to the guerrillas that until they sign peace, they remain an illegal organization that is investigated by the courts and unable to be involved in politics through their perverse practice of mixing weapons with politics," the interior ministry said in a statement.
The protesters want to be able to farm coca without government hindrance, as well as substantial increases in spending on roads, health, education and job creation. President Juan Manuel Santos has sought dialogue with the protesters but things fell apart when they refused to lift their road blocks.
Police claim the rebels are behind the protests and have fomented the unrest but farmers deny that.
The government has been seeking a peace accord during talks in Cuba with the FARC but the group's apparent involvement in the protest has caused tension at the negotiating table as the two sides discuss rebel involvement in politics.
FARC and government negotiators in May reached agreement on agrarian reform, one of the thorniest on a five-point agenda that also includes the drug trade, compensation to victims and an end to the conflict. Talks began in November.
"It's true that we have entered into a process aimed at ending the conflict and constructing a stable and lasting peace," the Magdalena unit of the FARC said in its statement. "But rest assured that while the Colombian people continue to be violated as today, such an agreement is impossible."
Even as a decade-long U.S.-backed offensive has weakened the drug-funded group and halved its numbers to about 8,000 fighters, the FARC remains a formidable force.
Patience with the FARC, considered a terrorist group by the United States and European Union, has deteriorated in recent weeks after an escalation of violence that culminated this weekend in the death of 19 soldiers and the announcement that it had kidnapped a U.S. citizen.
Fifteen of the soldiers were ambushed by the FARC as they protected an oil pipeline under construction and four others were attacked in the south of the country.
Local media reported that some of the soldiers were shot execution style.
Many Colombians and opposition lawmakers are worried the government will offer too many concessions in its eagerness to bring an end to a five-decade war that has killed more than 100,000 and displaced millions.
The FARC, which has battled a dozen governments since it was established in 1964 as an agrarian movement, has become more political in recent months as it seeks backing from Colombia's vast rural community ahead of any peace accord.
(Reporting by Helen Murphy and Luis Jaime Acosta; Editing by Bill Trott and Philip Barbara)