FACTBOX - Facts about Colombia's FARC guerrillas

(Reuters) - Colombian rebels are at the centre of a diplomatic crisis in South America's northern Andean region as Ecuador and Venezuela order troops to the Colombian border.

On Saturday Colombian forces entered Ecuador and killed Raul Reyes, the No. 2 leader of the Revolutionary Armed Forces of Colombia, or FARC. The neighbouring countries accuse Colombia of violating Ecuadorean sovereignty in the raid.

Following are some facts about the FARC, Colombia's biggest rebel army.

* Reyes' death is considered the hardest blow ever against the FARC, which was established in the 1960s as a communist insurgent army aimed at reducing the wide gulf that still divides rich and poor in the South American state.

* The group has used the multibillion-dollar Colombian cocaine trade to fund its operations over the last 20 years. The conflict has been reduced in many regions to turf battles over lucrative cocaine-producing land involving the FARC, right-wing paramilitaries and other drug smuggling gangs.

* The FARC, branded a terrorist organization by the United State and European Union, has been pushed onto the defensive by conservative President Alvaro Uribe's U.S.-backed security policies. The United States has given Colombia $5.5 billion (2.77 billion pounds) in mostly military aid over the last seven years.

* But the FARC still controls some rural areas where it produces cocaine and keeps hundreds of kidnap victims hostage in secret jungle camps. The captives include three American defence contractors, taken in 2003, and French-Colombian politician Ingrid Betancourt, snatched during her 2002 presidential campaign.

* While crime falls and the economy grows in Colombia's central, north and northwest urban areas, the FARC's strongest presence is felt in the southeastern jungles. The group freed six long-term hostages in January and February as part of deals brokered by Hugo Chavez, Venezuela's leftist president.

(Reporting by Hugh Bronstein, editing by Patricia Zengerle)