The terror suspects arrested in Isiolo last month, one of whom had booked a hotel room for almost a week near the Central Police Station, were targeting the Judiciary buildings and a government installation.
Inspector General of Police Joseph Boinnet, revealing details of the foiled attack, which is probably one of the most successful arrests in recent times, said that the vehicle with registration number KBM 200D that was seized from the suspects in Merti, Isiolo County, was laden with approximately 80kg of high-grade Trinitrotoluene (TNT) explosives.
Mr Boinnet revealed that the vehicle, which would have been used as a Suicide Vehicle Bound Explosive Device (SVBIED), was set to be driven to Nairobi and would have killed hundreds of innocent civilians.
A police investigation revealed that one of the suspects, Abdimajit Adan, 24, had booked a hotel room near the Central Police Station 10 days earlier, and only travelled to Merti on the day he was arrested, leaving a note to the hotel management pleading for them to reserve the same room for him because he would be back.
He was arrested alongside Mohammed Nane on Thursday, February 15, after a brief exchange of fire.
Police found five AK-47 assault rifles, 1,099 rounds of ammunition, and 36 fully loaded magazines in their car.
A third suspect was killed at the scene in Yamincha, while two others escaped.
It emerged after the vehicle was towed to Nairobi for scrutiny that the suspects had laced it with eight projectiles and shrapnel materials around its body.
Each of the ranged weapon, according to Mr Boinnett, contains approximately 10kg of TNT.
The shrapnel in it include ball bearings meant to maximise causalities when it explodes.
"Typically, terrorists prefer ramming an SVBIED on a gate or main entrance to the target. To avoid premature detonation."
"This allows the second team of terrorist armed with AK47 assault rifles to stage a siege inside the target building," Mr Boinnett added, giving an example of the Kulbiyow and El Adde attacks where the SVBIED were used to stage attacks.
The police boss said if the terrorists had been successful, the SVBIED would have caused a high magnitude explosion that would have brought down a building frontal structure while the explosion wave would have killed hundreds of Kenyans.
"The bomb would have destroyed buildings, vehicles, and infrastructural structures nearby besides killing hundreds of people within a radius of 250 metres," he said during a press conference outside the DCI Headquarters' Forensic laboratory.
An expert attached to the Bomb and Hazardous Disposal Unit explained that just a kilogramme of TNT can cause destruction in up to 11 metres radius from the epicentre.
The recovered explosives weighed 100kg in total.
"The explosion would also cause massive traffic disruption and such an outcome would allow for another attack to take place," Mr Boinnet said.
The objective of the destruction and murder, the police boss said, was to spread fear, attract attention of local, regional and international media and to embarrass government security forces so that they overreact and appear repressive.
This would have also discouraged foreign investments, tourism, or assistance programmes thereby affecting the country's economy.
The police had three days after arresting the suspects in Merti, nabbed two more suspects and found them with receipts of two motorcycles.