The attack happened almost at the exact spot where four officers were killed in a similar attack yesterday, which has been claimed by al-Shabab militants.
Five other officers were killed in a separate bombing incident on Monday in neighbouring Mandera county.
Al-Shabab has staged numerous attacks in Kenya in recent years.
The Islamist militants want Kenya to withdraw its troops who are serving under the AU mission to Somalia (Amisom).
Kenya sent its troops across the border in 2011 to pursue al-Shabab.
The BBC's Mohammud Ali in Nairobi reports that the Mandera attack had targeted a convoy carrying local politicians including the county governor Ali Roba.
Mr Roba posted on Facebook on Monday that he had also lost his bodyguard in the attack.
It is the third attack that has targeted Mr Roba in three years.
Five Kenyan policemen have been killed after their vehicle hit a roadside bomb in the north-eastern town of Liboi, near the border with Somalia.