The president of Ecuador has imposed a state of emergency in the country over concern that the volcano Cotopaxi might erupt.
President Rafael Correa on Saturday said it was important to prepare by mobilising the necessary financial means and to concentrate other resources.
The measures theoretically mean there could be limits on freedom of assembly and news coverage.
Correa said security co-ordinator Cesar Navas was in charge of the measures and urged calm.
"In such emergencies panic is produced, and that creates more problems than solutions," Correa said.
Several villages in Ecuador have been evacuated as the Cotopaxi volcano rumbled to life, angrily spewing ash into the sky and threatening nearby residents with potential volcanic landslides.
Officials said the evacuations were ordered as a precautionary measure, as Cotopaxi became increasingly active, but that no landslides had yet been recorded.
Several towns and river settlements in Cotopaxi province, some 45km south of the capital Quito, were cleared, said Pablo Morillo, head of the Secretariat for Risk Management.
Authorities maintained a yellow alert in the region, a mid-range warning, and said it would remain as long as Cotopaxi continued to stir.
"We will maintain the same alert, but since there are still no lahar flows, the evacuation order is still only preventive," Morillo told AFP.
The volcano, which towers to 5,897 metres high , is considered to be one of the most threatening in the region - both because of its size and because it is so close to well-populated towns.
Cotopaxi registered several eruptions on Friday, following decades of inactivity, spewing ash columns as high as eight kilometres into the sky.
The volcano spewed a current of hot glass and rock - called pyroclastic flow - which authorities warned could trigger avalanches or landslides of volcanic debris, also known as lahars.
The Geophysical Institute cautioned residents: "At present there have been no lahars, but they could occur."
Quito Mayor Mauricio Rodas said one million surgical masks would be distributed across the city of 2.3 million people, to prevent inhalation of falling dust.
Cotopaxi is one of eight active volcanoes in Ecuador, a country that is part of the so-called Pacific Ring of Fire that makes it prone to seismic and volcanic events.