Kochi: A National Investigating Agency (NIA) court here on Monday sent six youths -- suspected to be activists of  Islamic State-- to the NIA's custody till October 14.

These youths -- all aged below 30 -- were arrested from north Kerela on Sunday. While five were picked from a remote location in Kannur, the sixth was held from Kozhikode.

The NIA told the court that these young men were part of a 10-member group, which the central agency was tailing for a while.

The NIA also told the court that it will probe whether the arrested accused had any role with respect to 21 persons, including women and children, who earlier went missing from Kerala and were now a part of the Islamic State in Afganisthan.

One of the arrested men had returned from Qatar 10 days ago. His wife and sister denied he had anything to do with the IS terror outfit.

"I don't think he has got anything to do with any terrorist organisation," said his wife, while his sister asserted her brother was not into such illegal acts.

The relatives and friends of the other accused too expressed surprise over the development.