By Subir Bhaumik
BBC News, Calcutta
Separatist rebels in India's troubled north-eastern state of Assam say that they have killed 14 people in two separate attacks.
The rebels, belonging to a group called Black Widow, said they have killed 12 people at a cement factory.
Two railway workers have been killed in another rebel attack. Police said they were yet to recover the dead bodies.
The breakaway tribal rebel group is fighting for an independent homeland for the Dimasa tribe.
The rebels have regularly attacked security forces and expatriate workers.
Morong Dimasa, who is described as the deputy commander-in-chief of the "Black Widow" group, told the BBC that five drivers belonging to the cement company and seven workers transporting cement had been killed in the attack in the North Cachar Hills district.
Wave of attacks
The police said the rebels may have dumped the bodies in the neighbouring jungles.
The rebels also stopped a train between the stations of Kalachand and Damcherra in the North Cachar Hills district and killed two railway employees, including the driver of the train.
Railway official Shambhu Prasad Choudhury said railway employees were being evacuated between the railway stations of Lumbding and Damcherra on the North Cachar Hill route.
The North Cachar Hills is the link between Assam's Brahmaputra and Barak Valley and train and buses between the two valleys have to take the hill route.
The Black Widows attacked a railway construction site at Fiding on Sunday and killed eight construction labourers.
Another railway employee was killed over the weekend. Two more were killed on Monday.
The Black Widows, who are fighting for a separate homeland for the Dimasa tribe, had maintained a ceasefire with Indian security forces for the past few months.
But last week, they alleged that Indian soldiers had attacked one of their camps and killed twelve Black Widow fighters in gross violation of the ceasefire.
This has been followed by a wave of attacks across the North Cachar Hills, that is seen as the "core" of the Dimasa homeland demanded by the Black Widows.