Ash spewing from Costa Rica's Turrialba volcano Monday forced the country's main airport to close for more than three hours, officials said.

Four flights to Juan Santamaria international airport were diverted and 10 departing flights were cancelled because of the ash, the airport's administrator said.

The Turrialba volcano, which has been intermittently active since 1996, erupted five times between Sunday and early Monday.

That sent smoke and ash over much of Costa Rica's central valley, including the capital San Jose, 80 kilometers (50 miles) to the east, according to National University's Vulcanological and Seismological Observatory.