Even as a CBI team continued its investigations into the Nandigram firing it is becoming increasingly apparent that a large number of 'armed outsiders' were involved in the clash, which claimed 14 lives.

The CBI investigations made a major breakthrough two days ago by arresting 10 persons hiding in a brick kiln and seizing a huge cache of arms and ammunition from them.

A member of the CBI team said on condition of anonymity that none of the arrested belonged to Nandigram, and that they had arrived from outside.

They were also caught with arms generally not used by the state security forces, he said.

The revelation contradicts the official theory that the clash took place when the police were attacked by villagers and fired in self-defence killing 14 persons and injuring scores on March 14.

To a question, the CBI team member also confirmed that a large number of spent bullets, recovered from the clash site did not belong to the category generally used by the police.

The bullets are used in countrymade weapons or by hunters.

Although local Communist Party of India-Marxist leaders in Nandigram are strongly denying the involvement of their activists, it is gradually becoming clear that those arrested by the CBI were party workers and a leader, Naru Maity, who is a known CPI-M activist.

Naru's father Debashis Maity has told the media that his son was an active CPI-M member, but expressed ignorance about his involvement in the clash at Nandigram.