There was some tense moments as two protesters doused themselves with kerosene and threatened to set themselves ablaze.Police arrested and removed them from the site.
The blaze, which destroyed the shed, was extinguished by fire force personnel.
Keezhattur is a marxist stronghold.
Hitting out at the CPI(M), environmental activist C R Neelakantan said it was ironical that while the marxist party was supporting the farmers protest in Maharashtra, it was trying to put down the agitation against taking over of paddy lands for construction of the NH.
Adivasi Gothra Mahasabha leader C K Janu said it was unfortunate that CPI(M), which was supporting similar protests elesewhere, was taking a different stand in Kerala.