Juan Segura, director of the country’s volcano and seismic observatory told reporters that the agency received numerous reports from area residents as the volcano triggered a seismic swarm northeast of Irazu.
The panic was in some way sparked by fresh video images of the earthquake and tsunami disaster to the south in Chile.
Irazú is adjacent to the Turrialba volcano, which has been actively spewing ash and gases for the last several months.
There have been 23 documented eruptions of Irazú with the first occurring in 1723.
The latest explosions produced by the mountain were in 1965 and 1963.
Photo: Costa Rica Tourism