Mandera residents have been warned against aiding militants behind attacks along highways and around the border.
Mandera County Commissioner Onesmus Kyatha says some locals are in constant communication with criminals in Kenya and across the border.
"I suspect that there are individuals within Mandera showing the armed militia group the route to their targeted areas," he said.
Cases of terror attacks within Mandera have escalated in recent weeks and efforts to combat it have been futile.
Mr Kyatha called upon locals to report any vital intelligence they might have to the authorities.
He regretted what he termed an "unpatriotic act" where some locals are aware of suspicious activities but chose to remain quiet.
"It pains me. It does not give me peace at all when such incidents occur. We must do whatever we can to stop them," he said.
Mr Kyatha alleged that some residents were sympathisers of the Al Shaabab.
"We must ask ourselves tough questions. There are some people inside us who are aiding these people. If our people continue doing that, then this war will never end," he said.
He said security agencies needed the support of the local community to defeat the rising crime wave.
The county commissioner made the remarks following the death of Engineer Ali Baricha, who was killed by unsuspected Al Shaabab militants while en route to Wajir on December 11.