Chief Superintendent Ismael Rafanan, Central Luzon police director, said the eight robbers entered the branch at about 1 p.m. yesterday and disarmed the lone security guard.
Rafanan said the suspects were well dressed and pretended to be customers.
Seven of the suspects entered the establisment while the others took the shotgun of the security guard at gunpoint.
Policemen near the Western Union noticed the presence of the robbers and reported it to the Mabalacat police station.
At around 1:30 p.m., the establishment was already surrounded by policemen, prompting the suspects to hostage the four personnel of the branch and the security guard.
Superintendent Nicanor Targa, Pampanga police deputy provincial director for operation, said the suspects first asked for media people to negotiate with them and gave the police a cellphone number.
An hour later, Senior Superintendent Leonardo Espina, Pampanga provincial police director, and Rafanan arrived at the scene and tried to negotiate with the suspects until they surrendered.
Five of the suspects were arrested but their three cohorts managed to escape while the negotiation was ongoing.
The arrested suspects were identified as Randy Ledaso, Nelio Pawela, Wilfredo Tavenia, Jaymar Reyes, and Abe Nunga, all natives of Samar.
Confiscated from them were two caliber .45 caliber pistols, a 9mm pistol and the security guard‘s shotgun.
Rafanan said a manhunt operation was launched against the three suspects who fled on board a motorcyle.