Ecuadorean authorities say 110 families have been evacuated from the vicinity of the Tungurahua volcano, which has been spewing molten rock, ash and lava since the weekend.
Spokeswoman Mercedes Taipe of Ecuador's Geophysics Institute says a column of vapor and ash up to 4km high has characterised the moderate-to-strong eruption.
She said Tuesday that a half-dozen villages are being showered in ash.
She had no immediate estimate on economic damage to local farming.
The 5023m volcano 135km southeast of Quito has been active since 1999.
In July and August of 2006 eruptions of Tungurahua killed at least four people, left two missing and forced the evacuation of thousands.