Four units of the commandos — each comprising 30-40 men trained extensively in jungle warfare — were airlifted from Orissa, home ministry sources said.

The CoBRAs — Commando Battalions for Resolute Action — will add sting to the five companies of CRPF that were sent to Bengal Tuesday amid reports that the Maoists have been planting landmines to block out central forces from the area. The CoBRAs completed training only a couple of months ago, and Lalgarh will be their first real test.

The decision to send CoBRA units came on a day Home Minister P Chidambaram said the Centre was “getting an impression that a section of the (state) government wants to act while the rest doesn’t fearing the consequences”.

As armed Maoists went on a rampage, the state police, ordered not to fire, deserted their posts. The state government fears firing on the mob might lead to a repeat of the Nandigram situation, which might then be exploited politically by the Trinamool Congress.

While sending in the CoBRAs, the home ministry has made it clear that maintaining law and order is primarily the state government’s responsibility, and the CRPF would only assist the state police. It has advised the Buddhadeb Bhattacharjee government to deploy its own security forces including the East Frontier Rifles and Special Armed Police alongside the regular police force.

Senior officials in the ministry, however, conceded that given the situation in Lalgarh, it was difficult to imagine the Bengal police taking the lead in operations against the Maoists and tribals, and in all likelihood it would be the CRPF that would take up frontal positions.

Till Wednesday evening, the deployment of the five companies of the CRPF which had reached West Midnapore was being discussed with state police officials. These forces come from the CRPF’s group centre in Sindri in Bihar, and are learnt to be experienced in handling mob violence. Many of the men now called in for Lalgarh had been deployed in Nandigram during the violent agitation against land acquisition earlier.