By Jatindra Dash

BHUBANESHWAR, India (Reuters) - Indian police killed at least 24 Maoist rebels in a remote, forested area of the eastern state of Odisha on Monday, police said, one of the heaviest casualty tolls suffered by the insurgents in recent years.

Acting on a tip-off, police tracked a group of around 30 Maoists who had gathered at a makeshift training camp close to the border with Andhra Pradesh state, officials said.

When the officers surprised the gathering shortly after midnight, a gun battle erupted.

"It was a makeshift training camp. Police have recovered 24 dead bodies of the Maoists during the search," Mitrabhanu Mahapatra, the chief of police in Malkangiri district, where the ambush occurred, told Reuters.

One police officer was killed in the gunfight that followed and another wounded, said Rahul Dev Sharma, superintendent of police in neighboring Visakhapatnam.

Maoists launched their insurgency in the 1960s and have been fighting from their jungle hideouts ever since.

The rebels accuse the Indian state of plundering the mineral-rich and underdeveloped east and central regions of the country at the expense of the poor and landless, among whom they retain some support.

While the level of violence has fallen in recent years, and the Maoists have lost hundreds of fighters to desertions and battles with security forces, the rebels remain capable of staging regular hit-and-run attacks across several states.

Police said Monday's gathering included senior rebel leaders, but said they could not confirm if they were among the dead until all the bodies had been identified.

The Maoists had not yet issued a statement on the incident via the website they have used in the past.

The security forces seized automatic rifles and ammunition from the area, a stronghold of the insurgents, police said.

According to the South Asia Terrorism Portal, 337 people have been killed in left-wing extremist violence so far this year, more than half of them alleged insurgents.

In July, Maoists killed at least 10 members of an elite Indian police force in the south of Bihar state.

(Writing by Tommy Wilkes; Editing by Sanjeev Miglani)