Twelve Lithuanian nationals were detained for violating a ban on trekking in the hills in the famous temple town on Thursday, and later let off, police said.
The foreigners, who had come to India on a pilgrimage had climbed the Deepam hills from Skandashramam near Ramanashramam, they said.
On receiving information, the forest department officials rushed to the spot and detained the group members, who told the officials that they wanted to visit the sacred hill and were not aware of the banon trekking.
However, they were let off after a warning.
Forest officials had issued a ban on trekking and also imposed restrictions on the number of people climbing the hill even during Karthigai Deepam festival following reports of foreigners going missing.
Twenty-two people of a 36-member team on a trekking expedition were killed in a forest fire in Kurangani hills in Theni district in March last.