Quito, Ecuador ? A senior leader of neighboring Colombia’s main rebel group was arrested in Ecuador, the nation’s police chief said Saturday, announcing the capture of the highest-ranking official of the leftist guerrilla army during nearly four decades of war.

A Colombian official said the United States played a role in the capture.

Ecuadorean Police Chief Jorge Poveda confirmed that Simon Trinidad was detained late Friday during a routine document check in Quito. He did not give any details about how long Trinidad had been in Ecuador or what he was doing there.

“Long live the FARC!” shouted Trinidad as he was escorted under heavy police guard to an army helicopter that left for Tulcan, a city on the Colombian border. Trinidad was swiftly extradited to Colombia.

Earlier reports from Colombia said Trinidad was captured at dawn at a medical clinic in Ecuador where he sought treatment for an undisclosed illness.

A Colombian military source said Colombian intelligence received information earlier that Trinidad was suffering from prostate cancer and had sought treatment in Quito. Eight agents tracked him to a medical clinic and notified Ecuadorean authorities, the source said.

Trinidad subsequently was identified as one of the seven members of the ruling secretariat of the Revolutionary Armed Forces of Colombia, or FARC.

Colombian President Alvaro Uribe praised the capture as evidence the country’s four-decade leftist insurgency can be defeated.

Colombia Defense Minister Jorge Alberto Uribe said the United States had a role in Trinidad’s capture, but declined to give details.

Simon Trinidad, center, one of the seven members of the ruling secretariat of the Revolutionary Armed Forces of Colombia, is escorted by Ecuadorean police while arriving Saturday at the airbase in Quito. Ecuadorean authorities captured the most senior Colombian rebel commander in four decades of guerrilla warfare.

The capture comes after the commander of the Colombian army, Gen. Martin Orlando Carreno, made it his New Year’s resolution to capture or kill at least one of the seven secretariat members within a year or resign.

The 54-year-old rebel, whose real name is Ricardo Ovidio Palmera Pineda, is wanted on some 30 counts of massacres, bombings and kidnappings.