Costa Rican officials have reopened the country's principle airport in the capital of San Jose after the eruption of the Turrialba volcano filled the sky with ash.

The Juan Santamaria international airport reopened around midday Friday after remaining closed through Thursday night. The Turrialba volcano erupted three times Thursday and state observers recorded a smaller eruption Friday morning.

Costa Rica's air security agency says the ash on the runways could pose a risk, as could the impaired visibility from the plume of ash.

The local Tobias Bolanos airport also was closed intermittently.

The country's public education ministry suspended classes Friday at 12 schools near the volcano.