Al-Shabab gunmen attacked Kenyan police vehicles near Somalia's border, injuring at least five officers and burning five cars, police have said.
Two officers were critically injured and three others sustained minor injuries in the attack in the north-eastern Garissa county, a statement signed by police chief JK Boinnet said.
Garissa police commander Shadrack Maithya said at least 13 police officers who had been missing following the attack had since been accounted for. Two of the attackers were killed, he said.
Another police official said the injured officers were part of a team of more than 20 officers travelling in three Land Cruiser pick-up trucks who had gone to recover a firearm lost by one officer whose car had been hit by a landmine. It is believed al-Shabab militants attacked the officers in the Land Cruisers, sending them running for safety, according to the police officer.
The statement by Boinnet said there was a heavy exchange of gunfire with the Islamic militants.
Al-Shabab, a Somali extremist group with links to al Qaida, said it carried out the attack, with a militant spokesman claiming 20 Kenyan officials had been killed.
The same area was in the spotlight last week after suspected al-Shabab militants raided mosques and started to preach to congregations of Muslims. The militants reportedly hoisted flags before the security forces arrived. Kenya's interior ministry said it had "thwarted an attempted attack" on Thursday evening after the residents of Yumbis spotted armed militants in the area and alerted the authorities.
Al-Shabab has carried out several attacks in Kenya in retaliation for the country's military involvement in Somalia.
In a separate incident, suspected al-Shabab militants ambushed a vehicle carrying four passengers in Lafey in the northern county of Mandera, wounding at least one person before seizing the vehicle and driving it towards Somalia, according to an official.
The Kenyan military said late on Monday that it had killed seven al-Shabab members inside Somalia.
The group claimed responsibility for an assault last month on a college in Garissa town in which 148 students were killed, as well as a 2013 attack on an upscale shopping centre in the capital, Nairobi, in which at least 67 people were killed.