Maoists have a presence in almost 200 Indian districts
A fierce gun battle between Maoist insurgents and security forces has taken place in the central Indian state of Chhattisgarh, police say.
They say that at least seven Maoists were killed in the fight, and one paramilitary soldier.
The clashes happened during an operation to remove more than 100 insurgents from a forest.
Thousands of people have died in the Maoist insurgency since it began in the 1960s as a backlash against poverty.
Chhattisgarh police chief RK Vij told the AFP news agency that more casualties were likely after an intense battle in the jungles of Singamadagu district, 500km (300 miles) south of the capital Raipur.
"Nine Maoists and an assistant commandant have died and five troopers are missing," he told AFP.
Some unconfirmed reports say that up to 30 Maoists were killed and 10 soldiers were missing.
Security officials in Raipur told AFP that up to 250 personnel from the police, paramilitary and commando units were involved in attacking a rebel arms factory in the Singamadagu offensive.
The rebels are believed to have established a parallel administration in the area and telephone communications there are virtually non-existent.
Indian Home Minister P Chidambaram told police chiefs this week that the guerrillas were growing stronger and refining their tactics in the forests of Chhattisgarh and had even acquired advanced military hardware.
India's Prime Minister Manmohan Singh on Tuesday also warned that his country was losing the battle against Maoist rebels.
The rebels - who operate in 182 districts in India - say they are fighting for the rights of the poor. They control large swathes of territory across central India.