Lamu East police boss Samson Obara said the soldiers were ferrying food to a military base in Somalia when they were ambushed by the attackers.
He says one of the militiamen was killed while others escaped on foot as their vehicle was blown up by the soldiers.
“We received intelligence report of the night attack that targeted a military truck that was ferrying food to a KDF patrol base in Ras Kamboni,” Obara told Capital FM News.
“A combined team of military and police are pursuing the militants, we suspect some were injured and even killed,” he said.
Last week, Al Shabaab attacked a convoy near the Somalia border in Mandera, leaving seven people including two policemen missing.