BOGOTA — Leftist guerrillas opened fire on a bus in Colombia, killing at least one person and wounding six others after its driver ignored orders to stop, police said Wednesday.

The attack occurred late Tuesday near the town of Valdivia in the department of Antioquia where FARC guerrillas had blocked a road with a parked truck, police said.

Police said the rebels flagged down the bus, but the driver tried to drive on, triggering the attack.

The bus was on a route between the town of San Carlos and Medellin, the provincial capital 420 kilometers (260 miles) northwest of Bogota.

The FARC — or Revolutionary Armed Forces of Colombia — has been in peace talks with the government of President Juan Manuel Santos since November, but the sides have made little progress and fighting has continued in the absence of a cease-fire.

The FARC, which is believed to have about 8,000 fighters, has waged an insurgency against the Colombian state since its founding in 1964.