Baldev said 15 persons had been rescued and search was on for others. Rescue operations are underway, and further details are awaited.
Of the survivors, 18 are injured, eight of them critically. He expressed confidence that all of them will be rescued by today.
Theni is located near Madurai.
State health minister C Vijayabhaskar said the injured trekkers were received at Kurangani by a medical team.
An Indian Air Force (IAF) helicopter from Sulur base has gone to the spot. At the moment, the Garuds are trying to lift the dead bodies to a higher plain.
Forest officials said the trekkers tried to take refuge inside a dried up stream but the dried grass in the stream quickly caught fire. Rescue operations have been expedited'.
The fire broke out in the Kurangani hills in the district of Theni, where a group of 24 people, mostly women, were returning from a trek organized to mark last week's International Women's Day.
The Kerala government has since chose to close down all wildlife sanctuaries for a safety audit, forest minister K Raju has said.
"'If we are informed in advance, we will give them the necessary arrangements".
"A simple guide will not do", he said.
Many local residents and religious leaders also visit the offices seeking permission to enter the forests to perform rituals.
The Fire Department got information about the incident around 3 pm, said another fire official. No person will be allowed to carry matchboxes, beedis, cigarettes, lighters or other devices that can light a fire into the forest.
The Theni forest fire is raging since Sunday.
He said the trekking team could have climbed from the Kerala side also. The groups had started the trek on Friday. Seven students who suffered burn injuries have been admitted to the Government Hospital at Bodinayakanur in Theni, said the Station House officer, Inter State Intelligence Wing, Theni.