The branch, located along Quirino Avenue in Barangay La Huerta, is some 100 meters away from the Police Community Precinct 2.
Apart from seizing cash from the counters, the suspects also took cellular phones from clients and bank tellers. They were not able to get to the bank vault.
After the heist, the suspects walked away in separate directions two in the direction of Kabihasnan and three toward Baclaran. They later used a motorcycle and a jeep to complete their get-away.
This was the fifth bank heist in the city this year, three of them involving Union Bank branches.
Suprintendent Ronald Estilles, Parañaque City police chief, said yesterday they have identified one of the suspects as Noel Inacmal, a resident of Block 19 Welfareville Compound, Barangay Addition Hills, Mandaluyong City.
"Witnesses identified Inacmal as one of the suspects. He is the same suspect in the April 4 Equitable Bank robbery in Makati City and was one of the robbers who allegedly hit the Union Bank branch in Tambo, Baclaran last Sept. 23," he said.
The suspect is a native of Ozamis and believed to be a remnant of the Kuratong Baleleng. He has a standing warrant of arrest issued by a Mandaluyong court for frustrated murder," said Estilles.
Later, two other suspects were identified, namely: Wilfredo Peñamayor and Ramil Besin.
Based on the description of witnesses, they have also made three other cartographic sketches Four of the suspects carried caliber .45 pistols while one had a caliber .38 revolver.
Parañaque City Mayor Joey Marquez, who visited the crime scene, said he is wondering why UnionBank has become the favorite target of the robbers.
"Kailangan maintindihan kung bakit suki ang Union Bank. I have instructed the police to look deeper into this," he said.
Union Bank branches along West Service Road, South Superhighway and a branch in Tambo, Parañaque were also hit this year.
Estilles noted that despite the repeated heists, management of Union Bank continues to post only one security guard.
Coincidentally, it was the same guard Robert Sangco of the Roque Security Agency who was posted at the Tambo and La Huerta branches when the robberies took place.
"We would have to place him under investigation and determine if there is a connection," he said.
Inspector Glenn Tigson, Parañaque police Criminal Investigation Division chief, said a bank should have at least two security guards. "One should be on guard, while the other frisks clients coming in."
Estilles said that when they tried to test the banks alarm it malfunctioned. "We learned about the robbery 20 minutes after the suspects left. They should have pressed the alarm while the robbery was in progress. It was a traffic enforcer who was the first to inform the police."