Elaborate security measures have been put in place in Tana Delta Sub-County following reports of massive recruitment and oath ceremonies by the Mombasa Republican Council (MRC).
Deputy County Commissioner Mike Kimoko on Wednesday said investigations have been launched to determine the motive for the latest round of recruitment by the MRC and possibly other illegal groups.
"We are trying to establish the driving force behind the fresh recruitment, particularly in Katsangani and Meticharaka. We have beefed up intelligence gathering and surveillance," said Mr Kimoko.
He said security officers acting on a tip-off had arrested 10 suspected MRC members who were on Wednesday charged with unlawful assembly, among other counts.
Mr Kimoko said the 10, who were on their way to Chonyo in neighbouring Kilifi County, had assorted incriminating items on them, including MRC membership cards.
"They were being driven in a vehicle that our officers had been trailing for a while," he said.
Mr Kimoko said more suspects were being sought in and outside Tana Delta and security officers had been deployed in areas where the alleged recruitment is reportedly taking place.
"We cannot rule out that the group is recruiting members to raise funds and to create chaos ahead of next year's General Election but we are ready for them," Mr Kimoko said.
He said the group, which the government has linked to Somalia's Al-Shabaab, could be plotting to cause violence in the area.
"We are on top of things and I urge the public to continue living together in harmony and report any suspicious elements to the police," he said.
Previous government reports indicate that dozens of youth from Tana Delta had been enlisted by Al-Shabaab and the MRC.
Last year, Mr Kimoko said some of youth who disappeared in 2012 and early 2013 had joined Al-Shabaab and the MRC.
He said initially, their families and neighbours suspected they were killed in clashes between the Pokomo and Orma communities.
However, it emerged that some of the youth were killed in November last year during a foiled attack on the 47 Kenya Army Rifle Nyali Barracks.
"There are families that cannot precisely tell the whereabouts of their kin. It is a matter of concern and we have sent a passionate appeal to everyone who cannot account for their loved ones to report the matter to us," said Mr Kimoko.
Six of the attackers killed in the dawn attack on the KDF barracks were residents of Galole and Bura constituencies who went missing during the Tana Delta clashes.
At least six other people facing robbery with violence and murder charges in Mombasa courts are from Garsen and Galole constituencies.