Kerala and Karnataka have temporarily banned trekking in forests after a fire in the Theni district of Tamil Nadu on Sunday evening killed 10 trekkers. Multiple groups of trekkers, including students, were trapped in the forest fire in Theni.

Tamil Nadu Chief Minister Edappadi Palaniswami had said the trekkers had not taken the required permission to be in the area, and the local forest chief had called it an “illegal trekking expedition”.

Kerala’s Forest Department restricted entry into wildlife sanctuaries until forest officers ensure the safety of visitors and clear all fire lines. Fire lines are strips in forests where vegetation is cleared to stop a possible fire from spreading.

The department said no one would be allowed to enter forest areas without its permission, The Hindu reported. Visitors would also be asked to watch a presentation on areas prone to forest fires and how to prevent them.

Karnataka banned treks in forests until the dry season ends and rain helps damp the ground in forests, The New Indian Express reported. The Forest Department said several forest areas in the state were prone to fires.

Fires have been reported in forest areas in Nandi Hills, Turahalli, Kodagu and Chikkamagaluru this year already, according to Bangalore Mirror.