Indian police have arrested six members of an Islamic State-inspired group suspected of plotting attacks on key figures and public places during the Hindu festival of Diwali, the national counter-terrorism agency said on Monday.

Islamic State has struggled to win over many recruits in India, which is home to the world's third-largest Muslim population.

But over the past year or so, the National Investigation Agency has found small groups of people in the southern states of Kerala and Tamil Nadu who have either travelled to Syria to join the militant Sunni group or planned attacks inside India.

On Sunday, the NIA picked up six men while they were in a meeting in a hilltop shrine in Kerala and said they were gathering explosives and other material to mount attacks in southern India during Diwali later this month.

‘During the searches, incriminating material including electronic devices have been seized from their possession and search of their premises,’ the agency said in a statement, calling them members of an ‘Islamic State-inspired terror module’.

The men were between the ages of 24 and 30, an official at the agency said. Reuters was not in a position to independently confirm the police claims.

Earlier this year, investigators said 12 men, six women and three children went missing from Kerala and were later believed to have joined Islamic State.