New Delhi, Jan 20 (PTI): Hindus and Christians converted to Islam besides Muslims were among 52 people arrested for allegedly being ISIS terrorists, the National Investigation Agency (NIA) said today, adding they included engineers and post-graduates.

Almost 80 per cent of the accused had formal schooling and rest went to Madrassas, it said.

The agency registered a highest of 12 Islamic State (ISIS) terrorism-related cases and arrested these accused last year. It is the highest number of cases and arrests made by the NIA in a year since its inception in 2009. In 2015, only two such cases were registered, the NIA said.

Those arrested for allegedly being ISIS operatives were of different age group. A total of 28 were in 18-25 year group, 20 between 25 to 40 years and four were above 40 years, it said.

A highest of 20 accused were graduates or engineers, 13 were matric passed, 12 were diploma holders, four were senior secondary passed while three were post-graduates with Master of Arts or Master of Computer Application degrees, the NIA said whe releasing data on the arrests.

Giving details of the religious affiliations of the accused, the agency said 50 per cent belong to 'Ahle Hadith', 30 per cent to 'Tabligi/Jammat' and 20 per cent followed Deobandi.

Of these 52 Islamic State-influenced persons held by NIA, 85 per cent of them are Sunni Muslims and rest are converted from Hinduism and Christianity, a senior NIA official said.

These persons hailed from various states across the country. A highest of 12 belonged to Maharashtra, 11 from Kerala, 10 from Telangana, five from West Bengal, four from Uttar Pradesh, three from Tamil Nadu, two from Rajasthan and one each from Jammu and Kashmir, Madhya Pradesh and Rajasthan.

Those arrested by the probe agency were of different income groups. As many as nine were from upper-middle income group, 30 from middle-income group and 13 from low-income group, the official said.

In 2016, a highest of 34 cases were registered by the NIA. Of these, 21 were related to Jihadi terrorism, five related to Fake Indian Currency Notes (FICN) and terror funding, three related to north east insurgency and two relating to Maoists, among others.

As many as 112 accused were arrested in these cases. Of them, 64 were held for their alleged involvement in Jihadi terrorism, 17 for north east insurgency, 12 for FICN and terror funding and three for left wing extremisms.