"I can confirm 10 officers were seriously injured," regional police chief Aggrey Adoli told AFP, saying the attackers may be linked to Somalia's Shebab Islamist insurgents.

He said police had shot dead one of the assailants while the other was killed by one of his own grenades.

The raid was carried out in Likoni on the coast south of Mombasa following a tip-off, and police recovered two firearms, two live grenades and ammunition, he said.

Kenyan police have in recent days launched a crackdown on members of the Mombasa Republican Council, a separatist group. On Monday two people were killed as police arrested MRC leader Omar Mwamnuadzi.

However Adoli initially ruled out any link between Wednesday's incident and the MRC.

Suspected supporters of the Al-Qaeda linked Shebab have also carried out attacks over the past year in Coast province, a popular tourist region, with bars and churches among their targets.

Shebab sympathisers have also attacked police in other parts of the country.