Patna, May 19 (IANS): Concerned over the safety of over 1,100 Indian workers, including those from Bihar, facing trouble in Angola, Chief Minister Nitish Kumar has sought Prime Minister Manmohan Singh's intervention to resolve the crisis.

"The situation is serious enough to warrant immediate intervention by the Indian government. The government should ensure that a fair treatment is meted out to the labourers, their wages are paid and they are given assistance for returning home, if they choose to do so," Nitish Kumar said in a letter to the prime minister.

The chief minister also requested Manmohan Singh to direct the authorities concerned to take prompt action for the release of labourers being prosecuted for several offences in the southern African country.

"Anxious relatives of some labourers from Bihar have reported that injured workers are deprived of proper treatment. Their passports have been impounded by the company they were working with," Kumar said.

An official in the chief minister's office said some relatives of workers approached the state government seeking help for safe return of their kin from Angola. "After that, the chief minister sought the prime minister's intervention," the official said.

The Indian workers are employed in a cement factory at Sumbe in the southern African country and there has been labour unrest at the factory due to non-payment of certain emoluments to them.

The $860 million cement project employs about 1,260 workers of whom 1,100 Indians were recruited by Dubai-based ETA Star.

The trouble has been festering since February this year, but it took a turn for the worse earlier this month when the Indian workers "became very restive" and clashed with the company officials.

This led to local police charging 59 Indians under several offences and initiating prosecution.