Southern Chile's Calbuco volcano has erupted for the first time in more than four decades, sending a thick plume of ash and smoke several kilometres into the sky, local television images showed.
Chile's Onemi emergency office declared a red alert following Wednesday's eruption, which occurred about 1,000km south of the capital Santiago near the tourist town of Puerto Varas. The area is sparsely populated, with only a few small communities.
Video footage of the eruption, which occurred at around 6pm local time (21:00 GMT), showed a spectacular mushroom-shaped cloud of ash and smoke, that turned red as the sun went down.
About 4,000 people had evacuated from the area and an evacuation radius of 20km has been established, authorities said.
