Dead on arrival at the Pasay General Hospital were Roberto Navarra, 30, alias "Bitong" of the Sputnik Gang, and Roberto Santos, 45, alias "Hapon" of the Batang City Jail (BCJ).
Investigation showed that the rumble started after a member of Sputnik, identified as Enrico de Asis, allegedly stabbed BCJ member Randy Ponferada in the left arm and shoulder at the first floor of the jail at around 6:30 p.m.
Jail operations chief Inspector Asyncrito Encio said Ponferada called on his fellow BCJ members and retaliated.
The hour-long gang war resulted in the death of Navarra and Santos.
Jail officials said Navarra sustained multiple stab wounds in different parts of the body, including his face, chest and upper back while Santos suffered a stab wound in the neck and a broken jaw.
Out of the 753 inmates in the city jail, there are 328 Sputnik and 220 BCJ members.
The two groups, who had previously been involved in riots, used improvised bladed weapons and paddles in the rumble, Encio said.
"We never allow any weapons to enter the premises of our jail. Their knives were improvised," he explained in a phone interview.
Police also said they were shocked to learn that inmates even used sharpened toothbrushes as weapons.
Encio noted that they have raided the cells and confiscated all improvised weapons. – Edu Punay