Three people, including a Rapid Deployment Unit officer, were on Monday evening shot dead by suspected bandits between Kapedo and Lomelo villages in Turkana East Sub-County.
Turkana County Police Commander Samuel Ndanyi said at least 14 others were injured during the 5.30pm attack.
"Armed bandits took advantage of the poor state of a section of the road to ambush the vehicle; a police officer and a civilian died on the spot," Mr Ndanyi said.
He said officers from the General Service Unit and RDU were immediately deployed to the scene to pursue the bandits.
While addressing journalists in Lodwar Tuesday, MPs Mohammed Ali Lokiru (Turkana East), Christopher Nakuleu (Turkana North) and Joyce Emanikor (Turkana Woman Rep) claimed that the attack was well planned.
Mr Lokiru said the police vehicle was transporting workers to a construction site at Kamosing area.
"The lorry was transporting Turkana locals and police [officers]," The MP said.
He said that there were intelligence reports of an impending attack in the area. Mr Nakuleu called on the police to conduct thorough investigations into the attack.
"Police must also conduct a disarmament exercise to rid the area of illegal firearms that promote banditry attacks," he said.
He called on the Ministry of Interior to restore security along the borders of Turkana and Baringo counties.
Ms Emanikor condemned the attack and called on the government to beef up security in Tiaty Sub-County.