Flights were suspended because of poor visibility at the airport yesterday, which is about 80 kilometres (50 miles) from the volcano, while pedestrians in the capital shielded their eyes to prevent ash going into them.
A number of schools sent students home and the country's emergency bureau ordered the evacuation of villages within two kilometres of Turrialba.
Turrialba erupted twice on Sunday, followed by a burst of activity Wednesday and then again yesterday.
