"I'm going back to see my house and animals. But we cannot be too careful with this volcano," said Gerardo Ruiz, a peasant who left his house in the village of Bilbao tucked on the folds of the 16,460-foot (5,020-metre) volcano.

During the cold night, evacuees slept in schools and churches as the volcano's activity slowed. But scientists warned it remains unpredictable.

In 2006, streams of fast-moving molten rock enveloped several hamlets on the mountainside, killing at least four people and forcing thousands to evacuate and abandon their corn and potato crops.

Wednesday's explosions of fiery rock did not harm any villagers, but the red-hot material flowed next to mountain hamlets through streams, emergency officials said.

"The flows passed right next to some of these communities, like Bilbao," said Marcelo Villagomez, the civil defense chief in the province of Chimborazo were part of the volcano lays.

"What people are doing now is tendering their land during the day and returning to shelters at night."

In nearby Banos hot springs, popular with foreign tourists, businesses were open as usual with hotel owners sweepings sidewalks and restaurants offering hot breakfasts.

In 1999, 17,000 people were forced to evacuate the town of Banos after an eruption triggered loud explosions and blew hot gas from the volcano.