Colombia ? Troops killed a senior commander of Colombia’s largest rebel army in an air-and-ground raid Saturday, as the U.S.-backed military dealt a stunning setback to the nation’s leftist insurgency.

Raul Reyes was the official spokesman for the Revolutionary Armed Forces of Colombia and considered a possible successor to the leftist group’s No. 1 spot. The United States had offered a $5 million reward for his capture.

Reyes, 59, died in combat and air strikes in neighboring Ecuador, Defense Minister Juan Manuel Santos told a news conference.

“This is the strongest blow dealt to the terrorist group to date,” Santos said.

There was no immediate reaction from the FARC.

Santos said the military tracked Reyes’ location through an informant. The air force bombed a camp on Colombia’s side of the border where he was thought be, but as ground troops moved in, they came under attack from another camp across the frontier. Reyes was found dead in the base in Ecuador.