A man has been charged with murder after two police officers were fatally shot in their patrol cars in "ambush style" attacks in Iowa.

Officers found the first victim, from the Urbandale Police Department, after responding to reports of shots being fired shortly after 1am local time on Wednesday.

About 20 minutes later officers found a DMPD officer, who had also been killed, two miles away.

46-year-old Scott Michael Greene was taken into custody just hours after police named him as a suspect.

Greene has been charged in connection with the deaths of Des Moines Sergeant Anthony Beminio and Urbandale officer Justin Martin.