ESCUINTLA, GUATEMALA -- About 500 residents evacuated voluntarily from the slopes of Guatemala's Volcano of Fire Tuesday as red-hot rock and ash flowed down the slopes toward an area devastated by a deadly 2018 eruption.

The National Institute of Seismology, Vulcanology, Meteorology and Hydrology said in a statement that around 3 a.m. Tuesday the volcano's activity began to diminish.

鈥淭he seismic and acoustic sensors confirm that the activity that persists in the crater are weak explosions and booms that still generate some avalanches principally toward the Ash and Dry ravines,鈥 the institute said.

Guatemala's disaster agency said shelters had been opened for the evacuees in the nearby town of Escuintla.

At one of those, a gym converted to a shelter in the community of Santa Lucia Cotzumalguapa, residents of surrounding communities rested on cots waiting to hear it was safe to return to their homes.

The 12,300-foot (3,763-metre) high Volcano of Fire is one of the most active in Central America and an eruption in 2018 killed 194 people and left another 234 missing.

The biggest danger from the volcano are lahars, a mixture of ash, rock, mud and debris, that can bury entire towns.