Bhubaneswar, May 5 (IANS) Production in Orissa's state-owned National Aluminium Co Ltd (NALCO) mine has dropped by at least 35 percent as workers have refused to do night shifts following the Maoist attack April 12, officials said Tuesday.

'Earlier workers use to work till 10 p.m. Since there is a cut of about five working hours, we are suffering production loss,' P.K. Mohapatra, head of the Damanjodi refinery and mine, told IANS.

He said the production of bauxite from the mine has come down to 9,000 tonnes per day from 14,000 tonnes.

Production was stopped for several days after Maoists rebels attacked the Panchpatmali mine in Koraput district, some 370 km from here. At least 10 security personnel and four Maoist guerrillas were killed in a gun battle.

Over 100 armed rebels had laid siege to the mine, took around 60 mine workers hostage and attacked a Central Industrial Security Force (CISF) camp. They had also looted explosives from a depot the CISF personnel were guarding.

NALCO is Asia's largest integrated aluminium producer. The bauxite from Panchpatmali mine feeds the refinery at Damanjodi town located nearby. The mine, which was shut after the attack, re-started work April 22 after company authorities agreed to the workers' demand that there would be no work after 5 p.m.

Mohapatra said that if bauxite production continues to reduce for longer periods, 'the plant may not be able to maintain its stock and may reduce alumina production'.

'At this moment we have a stock of about 300,000 tonnes of bauxite at the refinery against our normal stock of 400,000 tonnes. The existing stock will last for nearly two months,' the official said.

'We are negotiating with the workers, requesting them to join the night shift as early as possible to avoid this situation,' he said.

Mohapatra added that the company has taken several steps to ensure better safety and security of the workers.