Singur's fragile peace is tottering on the edge. The uneasy calm nearly blew apart on Wednesday morning when a group of Trinamool Congress supporters roughed up a few workers on way to the Tata Motors small car factory site. Some hours later, a group of men carrying Trinamool flags tried to storm the factory gate but was stopped in the nick of time by party leaders.

The group of nearly 30 workers, who were heckled and threatened by Trinamool supporters decided not to return to work till normalcy returns. Raj Kishore and Arvind Kumar Yadav share a room in Singur but were forced to return by the demonstrators from the site.

"We have worked in many projects across the country. This is the first time we have faced anything of this sort. Some of our colleagues were beaten up. The remaining were heckled and threatened," said a visibly shaken Kishore.

His friend said that they have no plans of returning to the factory. "It was very scary. We shall not return to work till normalcy returns," Yadav said. A labourer lodged a complaint with the police against the demonstrators. So did van rickshaw driver Pradip Das.

Engineers and technicians who were driven into the factory in cars and buses, sounded slightly more confident, though all of them spoke against the demonstration. "The things going on here in the last few days is unimaginable. I always dreamt of working for such a project. I don't know what these people want. After the project is completed, these people will realise the mistake they have made," said a young engineer.

Trinamool leaders denied that any of their supporters were involved in the attack. They maintained that it was a bid by the CPM and the state government to defame their 'peaceful' dharna.

The incidents have also rattled Trinamool leader Mamata Banerjee as she realised how brittle her assurance of a peaceful agitation was. With patience running out, Banerjee is realising that a single flashpoint could turn her movement into a free-for-all.

Meanwhile, with around 20,000 truck drivers stuck on the Durgapur expressway, the West Bengal Federation of Truck Owners Association will block NH6 for an indefinite period from Thursday.