Eight people were hurt before noon Sunday when a bomb exploded in General Santos City, security officials said.
The official number of casualties was earlier reported to be seven.
Philippine National Police spokesperson Senior Superintendent Benigno Durana said the explosion occurred at 11:40 a.m. at a pharmacy near Hadano Park on Crossing Makar, National Highway.
Lt. Col. Ezra Balagtey, spokesman of the Armed Forces' Eastern Mindanao Command, said none of the victims was in critical condition.
"Seven civilians were slight wounded, non-critical, all at lower extremities," Balagtey said, citing diagnosis conducted at the St. Elizabeth Hospital where the victims were taken for treatment.
The PNP later identified eight victims: Jeslly Yvonne Guyos, Anthon Faller, Claire Uozoia, Joana Bliss Alipio, Ially Jean Alipio, John Lenon Calong, Felipa Abella Regios, and Marlon Yadao Orabia.
"It was an IED but as to the component, we still don't know," Balagtey said when asked about the type of explosive used.
"There is ongoing post-blast investigation to determine the signature and identity the group [behind the attack]."
In a separate statement, PNP Director General Oscar Albayalde said that one of the victims is a six-year-old girl.
"I have directed the mobilization of all available police security forces in pursuit operations against persons responsible for the latest act of terrorism in General Santos City this morning even as we extend our support and sympathies to our fellow Filipinos who were wounded in the explosion incident," he said.
"I have once again strongly directed our police units in SOCSARGEN to further intensify conduct of checkpoints, police visibility patrols, and focused intelligence and law enforcement operations in close coordination with the rest of the members of the security sector," Albayalde added.
He also urged citizens with any information to come forward and help the police in its investigation.
The Bangsamoro Islamic Freedom Fighters (BIFF) have been reported to be planning to bomb General Santos City as well as Koronadal and Cotabato cities and Midsayap, Cotabato.
The blast occurred even as Mindanao is under martial law. —with Merlyn T. Manos and Jon Viktor Cabuenas/KBK/BM, GMA News