ESCUINTLA, Guatemala — A long-simmering volcano exploded into a series of powerful eruptions outside one of Guatemala's most famous tourist attractions on Thursday, hurling thick clouds of ash nearly two miles (three kilometers) high, spewing rivers of lava down its flanks and prompting evacuation orders for more than 33,000 people from surrounding communities.

Guatemala's head of emergency evacuations, Sergio Cabanas, said the evacuees were ordered to leave some 17 villages around the Volcan del Fuego, which sits about six miles southwest (16 kilometers) from the colonial city of Antigua, home to 45,000 people. The ash was blowing south-southeast and authorities said the tourist center of the country was not currently in danger, although they expected the eruption to last for at least 12 more hours.

The agency said the volcano spewed lava nearly 2,000 feet (600 meters) down slopes billowing with ash around Acatenango, a 12,346-foot-high (3,763-meter-high) volcano whose name translates as "Volcano of Fire."

"A paroxysm of an eruption is taking place, a great volcanic eruption, with strong explosions and columns of ash," said Gustavo Chicna, a volcanologist with the National Institute of Seismology, Vulcanology, Meteorology and Hydrology. He said cinders spewing from the volcano were settling a half-inch thick in some places.

He said extremely hot gases were also rolling down the sides of the volcano, which was almost entirely wreathed in ash and smoke. The emergency agency warned that flights through the area could be affected.

There was a red alert, the highest level, south and southeast of the mountain, where, Chicna said, "it's almost in total darkness."

He said ash was landing as far as 50 miles (80 kilometers) south of the volcano.

Teresa Marroquin, disaster coordinator for the Guatemalan Red Cross, said the organization had set up 10 emergency shelters and was sending hygiene kits and water.

"There are lots of respiratory problems and eye problems," she said.

Many of those living around the volcano are indigenous Kakchikeles people who live in relatively poor and isolated communities, and authorities said they expected to encounter difficulties in evacuating all the affected people from the area.

Officials in the Mexican state of Chiapas, on the border with Guatemala, said they were monitoring the situation in case winds drove ash toward Mexico.