Costa Rican authorities suspended operations at the country's main airports on Monday after the nearby Turrialba volcano erupted, sending a thick ash cloud into the sky.

The San Jose International Airport was temporarily closed for security reasons as the volcanic ash would've caused problems for planes, the Civil Aviation Authority said.

Airport sources said eight approaching flights were diverted to the north of the country and others to El Salvador.

Turrialba erupted twice on Monday; first at dawn and again just before noon.

The volcano is located 35 kilometres from the capital.

Operations at the Juan Santamaria International Airport, the country's main air terminal, and the Tobias Bolanos airport, were suspended until conditions improve, according to the chief of the Civil Aviation Directorate Ennio Cubillo.

"The particles are not only in the airspace but also on the surfaces of taxing and takeoff," he told local media.

Authorities also considered whether to limit the general aviation activities at the Daniel Oduber International Airport located in the northwest of the Central American nation.

Eight flights were suspended at the Santamaria Airport, from which an estimated 6,238 passengers departed Monday, according to Civil Aviation Directorate figures.

The volcano has already erupted several times in the past and threw a column of ash 4,000 metres into the air during the first eruption, followed by one about 1,000 metres high, according to the Volcanological and Seismological Observatory of Costa Rica.

The first eruption spewed incandescent rock more than 500 metres high, along with gas and ash, that reached Central Valley communities, about 70 kilometres away.