Police are holding two men suspected of masterminding two grenade attacks on security agents in Mombasa.
Three security officers were killed in separate attacks and 20 wounded.
The suspects are said to be among Kenyans trained by Al Shabaab in Somalia and sneaked back into the country early this year.
Coast Provincial Police Officer Aggrey Adoli said one of the men was arrested hours after the Wednesday night attacks.
He added the second was arrested on Thursday over the attack in Kisauni where three prison warders were killed.
“I can confirm we have two prime suspects and are dangerous people,” he said on phone. The attacks occurred as pockets of Muslim youth protested the killing of Islamic preacher Aboud Rogo where churches and business premises were destroyed.
Adoli said they have deployed security personnel in the area to address fears of chaos after Friday prayers. The same scenario is expected in major towns.
Police spokesman Eric Kiraithe said they have deployed enough personnel to stop any violence.
“We urge for calm and peace. Let them not use the word freedom to disrupt other people’s freedoms,” said Kiraithe.
The joint team investigating the death will visit the murder scene on Monday.
On Wednesday, the team met Director of Public Prosecutions Keriako Tobiko in Nairobi and agreed on terms of reference and the logistical requirements.
Tobiko asked them to set base in Mombasa for the mission.
The group was directed to cover all acts of criminality from attacks on churches and businesses to the killing of law enforcement officers.
The team is composed of Jacob Ondari from DPP’s office as coordinator, Edwin Okello, Mercy Gateru and Victor Mule. Those from Independent Policing Oversight Authority are Vincent Kiptoo and Njeri Onyango, while Law Society of Kenya members are Eric Nyongesa and Mohamed Balala.
Commission of Administration of Justice will be represented by Yuvinalis Angima while Kenya National Commission on Human Rights will have Victor Kamau. Pius Macharia will represent police as the lead investigator.
“The team will submit investigations file and recommendations to the DPP within 14 days,” said Tobiko.
Commissioner of Police Mathew Iteere has denied claims police were involved in the killing of Rogo who was sprayed with bullets in his car in Bamburi.