At least four persons were killed after five robbers briefly took hostage several passengers of a bus and engaged police in a shootout in Quezon City Thursday.

Passengers of the JMK bus (Body No. 23, TWH-291) said the five robbers boarded the vehicle near Guadalupe in Makati City and announced the holdup after a few minutes.

"Mga apat o lima sila, may granada. Umakyat sila sa overpass sa flyover sa may Guadalupe tapos sinabi nila holdup. Dito na lang nagkaroon ng habulan (There were four or five of them. They had a grenade. They boarded the bus at the flyover near Guadalupe in Makati City then declared a holdup. Then there was a police chase)," passenger Celia Mamaril told dzBB radio.

Two of the fatalities were found dead in the bus. The other two were reportedly killed after commandeering a Mitsubishi Adventure AUV (CSX-806) in Valenzuela City.

However, witnesses at least one of the robbers still managed to elude arrest.

Northern Police District (NPD) head Chief Supt. Pedro Tango said they had "taken into custody" four persons, but said one of them claimed to be one of the hostaged passengers.

In a separate interview on dzBB, Tango said that if the claim of the "hostage" were true, they will have to track down the remaining fifth suspect.

Mamaril said the bus, which plies the Malanday-Makati route, came from Makati City and was heading north along Epifanio delos Santos Avenue (EDSA).

Quezon City police who responded to the incident fired at the bus' tires to immobilize it. The bus sustained several bullet holes.

At least two men believed to be a driver and a passenger were found dead inside the bus. The driver was initially identified as Daroboy Santos of Angat, Bulacan.

"Maraming insidente nakapagmaneho pero ito ang pinakagrabe, namatay siya (He had experienced being victimized by robbers but this was the worst – he was killed)," said Santos' brother-in-law Federico Santos.

The third and fourth fatalities were shot while driving a commandeered Mitsubishi Adventure (CSX-806) near the Lawang Bato exit in Valenzuela City.

At least two other suspects were reported captured as of 11 a.m.

It remained unclear how many passengers were held hostage in the bus.

Traffic in the area was snarled as several police vehicles, followed by media news crews, sped to the site against the flow of traffic.

On the other hand, the police pursuit was hampered as toll gate employees at the North Luzon Expressway (NLEX) blocked some of the police vehicles and asked them to pay up.

Traffic at NLEX was also slowed after police and media vehicles were parked at the NLEX's outer lanes.