The Thane unit of the ATS arrested the six from Bhiwandi and they have confessed that they are Bangladeshi nationals who had been staying in the country illegally, an official said.
They have been booked under relevant sections of the Passport (Entry Into India) Rules, the Foreigners Act as well as the Indian Penal Code, he said.
Officials said the number of nationals from the neighbouring country apprehended by the state's ATS now stood at 24.
Among the arrested, five have also been charged with sheltering operatives of the Ansarullah Bangla Team (ABT), a terror outfit banned in Bangladesh, an official said.
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