A police spokesman told AFP following the explosion between Mararani and Kiunga, just a handful of kilometres (miles) from the border.
"We have eight victims -- four children and four police," a police spokesman told AFP following the explosion between Mararani and Kiunga, just a handful of kilometres (miles) from the border.
The blast bore the hallmarks of similar bombings blamed on Shabaab Islamists who have targeted security forces in the past in the region.
Seven police officers and a civilian were killed at the end of May when an armoured vehicle drove over a roadside bomb in southeastern Kenya, a week after 14 others died in three similar attacks the group claimed.
Across the border, the Al-Qaeda linked extremist group last week claimed responsibility after driving an explosives-laden minibus into local government offices in the capital Mogadishu, killing at least 10 people.
That attack followed hot on the heels of assaults on two Mogadishu restaurants which killed at least 18 people.
The group has also launched attacks in Uganda, which, like Kenya, contributes troops to a 22,000-strong African Union force in Somalia.