Two suspects in the Wajir terror attack that left 11 travellers dead will remain in police custody for 30 days for police to complete the probe.
The two are Musa Hussein Ramadhan and Sadiq Abdullahi Isack, the driver and conductor of the Medina bus that was attacked by suspected Al-Shabaab militants.
Among the victims were eight officers from the Anti-Stock Theft Unit (ASTU), who had been returning to their work station at Elram in Mandera County, and three people including a teacher and a doctor.
In a sworn affidavit, an officer from the Anti-Terror Police Unit (ATPU) said information gathered during the suspects' interrogation revealed other people were involved.
The officer said they therefore needed time to travel to counties including Garissa, Mandera, Rhamu and Nairobi to gather more information.
He told a Wajir court on Wednesday that they also needed to confiscate the suspects' phones and take them to the ATPU's headquarters for analysis.
The officer further said the suspects could not be released as they had shown signs of interfering with the probe.
Mr Ramadhan and Mr Isack were arrested after it emerged that a suspicious individual was seen making calls and moving from one seat to another while speaking to the crew until the time of the attack.
Authorities also want to find out why the driver stopped the bus instead of speeding off and how the militants figured out the identity of the passengers before targeting the vehicle.
Wajir Senior Resident Magistrate Mugendi Nyaga granted the investigators their prayers, noting the case was a matter of national security.
The case will be mentioned on January 12, 2020.
About seven suspected Al-Shabaab militants stopped the bus on a lonely stretch between Kutulo and Wargadud at about 5 pm on December 6.
The militants the travellers into two groups of locals and non-locals, executed the non-locals and let the others continue with the journey.
Six people escaped through the windows and ran for their lives. Authorities said the bus had 56 passengers.
Preliminary reports suggest that sympathisers helped the Somalia-based ragtag militia to coordinate the attack.
In an earlier interview, Wajir County Commander Stephen Ng'etich noted that local transporters were advised against using routes such as Wajir-Mandera to transport non-locals since they are easy targets.
"From Mandera, they are advised to use the Danaba-Bute and Moyale routes since buses from Mandera are not escorted to Wajir," Mr Ng'etich said.
On Wednesday, the requiem mass of the officers who lost their lives during the attack was held in Gilgil.