Manila Arson Investigation Department head Adan Bithao said the blaze started at around 12:15 a.m. from one of the houses along Luzon St. in Magdalena.
The fire immediately spread to the shanties in the crowded area and reached the fifth alarm around 15 minutes later.
Bithao said the blaze gutted at least P.3 million worth of properties before it was put out at exactly 1:42 a.m.
Before the fire started, another blaze hit a residential area in Hermosa, also in Tondo and gutted five houses.
According to Bithao, the blaze on Dela Cruz St. also reached the fifth alarm because firefighters had a hard time penetrating the affected houses, which were located at the innermost portion of a compound.
Bithao has placed the estimated cost of damage at P.25 million. The fire was put out at 1:44 a.m.
No one was reportedly injured in both fire incidents, he said.
Bithao said they have yet to determine the cause of the two fire incidents but stressed that affected residents in both areas heard explosions before the fire, prompting investigators to believe that the fires were both caused by firecrackers.
"Nagsimula yung sunog sa kainitan ng putukan kaya di natin maiwasang isipin na paputok ang pinagmulan (The fire started at the peak of the New Year revelry so we can’t help but conclude that the blaze was caused by firecrackers)," he explained.
Last Thursday, another fire hit the Old Happy Land compound along R-10 and left over 1,500 families homeless for the New Year.