Chile's Llaima volcano spewed lava and belched ash into the sky Sunday, prompting the evacuation of dozens of people and renewing concerns of a major eruption in one of the world's volcanic hotspots.

Seventy-one people were evacuated "because of risk from volcanic activity that have increased the volume of the Calbuco river and other waterways and swollen them with volcanic ash," the State National Emergency Office (ONEMI) said in a statement.

Five localities were put on red alert including Vilcun and Curacautin, where evacuations had begun after Llaima, one of the most active of Chile's 500 active volcanoes, began churning up lava and ash late Friday.

Military and police reinforcements were sent to the region, where the Conguillio national park was shut Saturday following LLaima's most significant activity since it erupted in January 2008.

"During the night, the volcano maintained its activity with explosions, lava flows, and expulsions of gas and ash," ONEMI said.

Acting Interior Minister Patricio Rosende, who arrived in the region Sunday to meet with emergency personnel and visit affected areas, described the conditions near the volcano as "uncertain" and ordered prompt evacuations if necessary.

The 3,125-meter (10,312-foot) Llaima is 700 kilometers (435 miles) south of the Chilean capital Santiago and just a few kilometers (miles) west of the Argentina border.

The Chaiten volcano -- some 500 kilometers (310 miles) further south along Chile's volcanic ridge that forms part of the Pacific "Ring of Fire" -- erupted last May for the first time in thousands of years, virtually destroying the town of the same name, forcing the evacuation of its 4,000 inhabitants and spewing ash across southern Chile and Argentina.

The Chaiten volcano rumbled back into activity in February, threatening to devastate the area with new pyroclastic flows.

That volcano's new eruptions came only days after the government said it would not rebuild Chaiten in the same location, despite protests from its inhabitants.