Chinandega, Nicaragua (CNN) -- More than 1,500 people have been evacuated after a volcano in western Nicaragua erupted Saturday, shooting gas and ash 2 1/2 miles into the sky, government officials said.
Explosions at San Cristobal Volcano -- located in the department of Chinandega about 65 kilometers (40 miles) south of the Honduran border and 130 kilometers north of the capital, Managua -- began around 8:45 a.m. Saturday, according to an assessment from SINAPRED, Nicaragua's federal emergency and disaster management agency.
"We have to be careful and take all appropriate measures for the families that are there and families from neighboring towns," first lady Rosario Murillo told the EL19 government-run newspaper. She said 400 families have been moved.
"I have seen it bring ashes, but not like now," Jose Espinoza, who lives near the volcano, said. "It surprised us because it is a powerful volcano and to see it like this would make anyone panic."
Jacinta Carazo, another resident, told CNN that an eruption in 2006 brought a lot of mud but this one was mostly ash.
"It got dark," she said.
Neither Espinoza nor Carazo has evacuated nor do they want to leave.
A story linked off Nicaraguan President Daniel Ortega's website indicated 20,000 people in surrounding towns could be affected.
About 3,000 people in five communities were already seeing gases and other effects after three large explosions on Saturday, SINAPRED director Guillermo Gonzalez said, according to the El Pueblo Presidente website.
Authorities say the main risk is the mix of rain, ash and gas that could affect the health of residents.
School classes have been suspended in Chinandega department through Sunday, education official Jose Tremino said.
At about 1,745 meters (5,725 feet), San Cristobal is Nicaragua's tallest volcano, and is part of a complex consisting of five volcanic edifices, according to the Smithsonian Museum of Natural History.
Prior to Saturday, the last known eruption of San Cristobal -- which is also known as El Viejo -- was in 2011, the museum said.
Journalist Samantha Lugo contributed to this report.