Some people including farmers had stopped revenue officers from taking up land survey work in Kannur for a highway expansion project. Forty of the protesters were arrested on Wednesday for obstructing the work of revenue officials.
The situation had to be handled carefully, officials said, as some of them had poured kerosene over themselves in their attempt to obstruct the land survey.
Sources said that soon after the arrests, the CPI(M ) activists allegedly burnt down the tents of the protesters for going against the party line. The area is a Left stronghold.
"A case has been registered against some of those who burnt the tents down, others are being identified. Action will be taken against them," a police officer said.
The Kannur district collector has called a meeting with the protesters on Thursday.
"The land owners have consented to the National Highway bypass acquisition. But there are some protests against the filling of paddy fields on environmental grounds. We have looked into several other options, but the other options involved displacing people in large numbers, which is why the paddy fields were selected as a last resort," Mir Mohammed Ali said.