The policemen were said to be part of those deployed from Osun State for the November 16 governorship election in Anambra State.
It was learnt that the truck they were travelling in was attacked by gunmen at the Benin bypass. Four of them were killed immediately.
It could not however be ascertained whether the attackers were political thugs or armed robbers.
Though effort to confirm the death from the Edo State Police Commissioner, Mr. Foluso Adebanjo, was fruitless, a senior police officer told our correspondent that the command had not been briefed about the incident.