He denied that any ransom was paid to release the hostages.
The employees and labourers were abducted Monday from Tewarpani village of Gumla district, 145 km from here.
Maoist rebels had also set 10 vehicles on fire including six trucks laden with bauxite.
The rebels on set trucks laden with bauxite on fire on a regular basis when they are denied levy.
Leftist guerrillas are active in 18 of state's 24 districts. Nearly 1,500 people have been killed in Maoist-related violence in the last eight years.