At least 33 suspected Al-Shabaab terrorists were arrested and two planned major attacks foiled in Tana River County between December and March.
County Deputy Commissioner Michael Kioni said last year, security agencies waylaid some 20 Al-Shabaab terrorists who were traveling by road to attack Jamuhuri Day celebration in Hola town.
Tana River Governor Hussein Dado and County Commissioner Isiah Nakoru were targets among other senior county and national governments officials.
He indicated that among the attackers were suicide bombers.
In an interview with the Nation, Mr Kioni said they received prior intelligence which helped them to thwart the attack targeted at the crowd attending the public holiday.
He said a team of security officers drawn from the military and Anti-Terrorism Police Unit (ATPU) intercepted the group along Lamu-Garsen Road and recovered assorted bomb making explosives.
According to Mr Kioni the suspected militants were mostly from Somalia and several were Kenyans drawn from across the country.
Two months ago security agencies averted a second plan by Al-Shabaab to destroy Safaricom communication masts in Bura trading centre and arrested 13 attackers among them a Ugandan, Mr Kioni said.
He said locals have been sensitised to remain vigil and alert security agencies in case they spot suspicious people either in foot or travelling by vehicles.
The county has three main bridges which are all manned by police and KDF.
They include Mororo Bridge which connects the county with Garissa which has been manned for decades by police and immigration officers to guard aliens from sneaking into the country.
Kenya military is also manning the Masalani Bridge which connects Tana River and Ijara sub-county in Garissa, which is highly suspected to be easily used by terrorists due to its proximity with Boni forest.
Police and the military are also manning Garsen Bridge in Tana Delta sub-county, which also connects Malindi and Mombasa towns.