Activists of the Communist Party of India (Marxist) or CPI(M) allegedly set tents of protesting farmers on fire for not toeing the party line in Kerala's Kannur district. 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.