Police were combing forests in the coastal state of Andhra Pradesh for the rebels when guerrillas opened fire, police superintendent Y. Nagi Reddy said.
The exchange of fire lasted about half an hour.
"Five men and four women rebels were killed on the spot," Reddy said, adding several weapons were recovered.
The guerrillas claim they are fighting for the rights of neglected tribes and landless farmers and are active in 15 of India's 29 states.
In the worst-hit central Chhattisgarh state, thousands of people have taken shelter in makeshift government relief centres to escape violence.

Copyright AFP (Agence France-Presse), 2006