At least eight Kenyan police officers were killed on Saturday after their vehicle ran over a landmine during a patrol near the border with Somalia, police said.
Police Inspector General Hilary Mutyambai said a landcruiser with 11 police on board "was hit by an improvised explosive device".
He did not give a toll but a regional police source told AFP: "We lost eight police officers in this attack".
They had been on patrol between Khorof-Harar and Konton in Wajir county on the border between Kenya and Somalia, Mutyambai added.
Kenyan media had reported an attack on Konton Friday by Islamist Al-Shabaab insurgents who kidnapped three Kenyan police reservists. AFP has not been able to confirm the information.
The patrol hit in Saturday's explosion was deployed in response to the reported incidents in Konton.
In June last year, eight Kenyan police were killed in a roadside bomb attack in the same region.
Wajir county and its neighbours Mandera and Garissa are frequently targeted in Shabaab attacks, notably security personnel deployed there to monitor the frontier.
The Al-Qaeda-linked insurgent group has claimed several similar attacks targeting Kenyan police and soldiers.
The Shabaab has been fighting since 2007 to topple Somalia's fragile government, which is backed by a 20,000-strong African Union force, Amisom.
The insurgents fled fixed positions they once held in Mogadishu in 2011, and have since lost many of their strongholds.
But they retain control of large rural swathes of the country and continue to wage a guerrilla war against the authorities.
The group has carried out a number of attacks in Kenya since 2011 in reprisal for the country's participation in Amisom.