A Sam Rainsy Party (SRP) activist was injured during a fight with at least four gunmen in Kompong Cham on Tuesday night.
The SRP has not determined whether the attack was politically motivated or an attempted robbery.
Police said the 61 year-old victim used his ax to fight back with the 4 men whom police suspected as robbers in his house which has a SRP banner in front.
Police said one suspect was shot dead during a shootout with border police who came to the scene when they heard the blast.