The killing happened along the Mendi highway.
Undialu said he had anticipated such an attack, which was why he came out in the media to warn the public not to interfere with issues affecting the people of Hela.
Governor Undialu said killing, robbery and rape is common along the Nipa-Mendi section of the Highlands Highway and leaders of the province need to come out and address this.
He said the name of the entire Southern Highlands and Hela province continues to be tarnished, thanks to a handful of troublemakers.
The Governor also offered condolences to the families of the late constables.
Police Minister Jelta Wong has also condemned the killings, saying deliberate attacks on members of the Police force will not be taken lightly.
Wong also said he will discuss with the Police Commissioner how best the RPNGC can manage such issues, with the possibility of instituting a firearms and ammunition moratorium, a State of Emergency for parts of the Highlands region, as well as further drafting of legislation to strictly deal with offences relating to the use of firearms, such as increasing penalties of custodial sentences from 40 years to life.