Police think a serial arsonist may be targeting farms in Järva County.
There are five criminal cases involving fires in the last 12 months. Three of the five buildings affected were feed storage facilities, ETV reported.
Tuesday night saw the latest fire - a hay storage building near the town of Türi.
The previous two cases, one in August and one on November 17, were also near Türi.
Many farmers in the county have invested in surveillance systems since the summer, ETV reported.