Singur, May 25: Trinamul Congress supporters attacked police guarding the Tata Motors plant site here today and hurled burning bundles of cloth at two watchtowers inside the boundary wall, setting them ablaze.

The guards fired 10 tear gas shells to disperse them.

“Several constables were injured by brickbats hurled at them. One of the constables has got a cracked skull. But we did not allow the mob to damage the boundary wall,” Hooghly district police chief Rajeev Mishra said.

The attack, with brooms sticks and burning cloths, was launched hours before Mamata Banerjee arrived here to address a rally on the second anniversary of the launch of the Trinamul Congress-led Save Farmland Committee’s movement against land acquisition in Singur.

Around 12.30pm, nearly 200 people, including about 50 women, ran towards the wall. As policemen came out of small openings in the wall, the villagers started pelting them with brickbats. “We still feel that the land where the factory is coming up is ours. We will break the wall anyday,” said broom-wielding Malati Malik of Bosepukur.

After the police burst the first few tear gas shells, some villagers hurled the burning bundles of cloth on the tarpaulin sheds of the watchtowers.

In her rally at Kamarkundu station, Mamata, described the attack as an “isolated” incident carried out by “a small section of villagers”.