At least five Kenyan police officers were killed in an attack on a region bordering Somalia.
At least two other police officers were also injured in the ambush on Tuesday, police said.
Insurgents sprayed a police patrol with gunfire near the border town of Liboi, leaving some officers badly wounded, in the latest in a string of attacks in the restive region.
"Five were killed on the spot when they were ambushed out on patrol, and we are told many bullets were fired on their vehicle," said a senior police officer who asked not to be named. "Others have been critically injured."
The identity of the perpetrators remains unclear, but such attacks against police and other targets are frequent along Kenya's porous border with Somalia and are routinely blamed by the authorities on the al-Qaeda-linked al-Shabab.
The region along Kenya's 700km border with Somalia has seen a series of attacks, mainly on police but also against hotels and restaurants.
Military base
Liboi, some 550kms northeast from the capital Nairobi, hosts a military base and is used by the army as a staging point to supply troops fighting al-Shabab as part of an African Union force inside southern Somalia.
"There is a heavy security presence now, more officers have been sent to get them before they cross the border," the officer added.
The attack comes as Kenya gears up to celebrate 50 years of independence on Thursday from former colonial masters Britain.
Kenya has said border security has been stepped up since al-Shebab claimed responsibility for Nairobi's Westgate mall massacre in September in which at least 67 people were killed.
They have been driven out of fixed positions from major towns in Somalia by the UN-mandated AU force, but still regularly launch attacks that include bombs and guerrilla-style raids. – Sapa-AFP