Bhubaneswar, March 11 (IANS) Security at power plants in Orissa has been increased after intelligence inputs of a threat from left-wing extremists, an official said Thursday.

'We have increased security for hydro and thermal power units. A few days ago we had discussed with home department how to beef up the security. We are ensuring the power plants remain secure,' an official of the state energy department said.

Last December, Maoists damaged a valve house of the Balimela Hydel Power in Malkangiri district, affecting power generation. Malkangiri is about 600 km from here.

Orissa has six hydro and two thermal power generation units.