At least seven Kenyan police officers were killed and 21 more were wounded Saturday as they pursued cattle rustlers in the north of the country, a police official told AFP.

"The officers were in a team pursuing stolen cattle when they were ambushed," said a senior officer, who did not wish to be named.

"Some of the bandits were wounded in the attack and others killed," during the gun battle, he added, without being able to give precise numbers.

Some of the wounded officers were airlifted by plane or by helicopter to Nairobi for treatment.

The attack happened near Baragoi, in a dry northern region mainly inhabited by nomad communities.

Cattle theft and the ensuing clashes between rival groups claim dozens of lives every year in Kenya.

It is rare however for police officers themselves to be attacked.