Anti-Terrorism Police Unit officers in Tana River are questioning two suspects over links to the January 2 Lamu bus convoy attack.
Three passengers were killed in the attack.
Mohammed Omar Ali and Abdalla Mohamed Abdalla were arrested on Monday.
Reports indicate the two had travelled from Mombasa to Hola and were heading to Garissa when they were apprehended.
On Friday, Tana River county police boss Fredrick Ochieng said one of the suspects was found with a laptop. He is an IT expert.
“The situation is calm now, and we encourage members of the public to report any suspicious persons around them," Ochieng said.
He said security around communication masts, churches, and schools had been beefed up.
“We have also intensified patrols in other social places which attract big numbers,” he said.
Security agents in the region warned that the militants are using poorly manned border points to sneak into the country.
Authorities at the North Coast have been on high alert after the Manda attack that led to the death of three US citizens. Five al Shabaab militants were killed in the attack.
While addressing the Annual National Security Review and Planning Conference in Mombasa last week, President Uhuru Kenyatta urged authorities to flush out terrorist operatives, especially in Northeastern and coastal regions.
“There should be an immediate restoration and securing of affected key government services in education, health, public transport, and communication infrastructure,” Uhuru said.
