Ranchi, Aug 18 - An operation has been launched to rescue ten employees and labourers of Hindalco company, abducted by Maoist rebels from Jharkhand's Gumla district, police said Tuesday.

Ten employees and workers of Hindalco were abducted Monday night from Tetarpani village of Gumla district, around 145 km from Ranchi. The rebels had also set ten vehicles on fire, including six trucks laden with bauxite.

The Maoists were demanding that the labour cost of loading and unloading of bauxite should be increased. They have also sought improvement of educational facilities in the district.

According to police, Maoist rebels abducted the Hindalco employees as they were denied extortion money.

Maoist guerrillas are active in 18 of the 24 districts of Jharkhand. Nearly 1,500 people have been killed in Maoist-related violence in the last eight years.