The deadly bombing of a night market in Davao that killed at least 14 was carried out by the Abu Sayyaf group of militants bearing allegiance to the Islamic State, authorities claimed on Saturday.
Philippines President Rodrigo Duterte, who was present in Davao, his hometown at the time of the incident, told the press earlier in the day that the blast was carried out in response to the military offensive launched against the Abu Sayyaf group the week before.
Davao mayor Sara Duterte, who is also the president's daughter, told CNN Philippines, "The office of the president texted and confirmed that was an Abu Sayyaf retaliation. For the city government side, we are working on that it is an Abu Sayyaf retaliation."
National defence secretary Delfin Lorenzana said the Abu Sayyaf group had struck back after suffering heavy casualty on its stronghold of Jolo island which is situated about 900 kilometres from Davao.
"We have predicted this and warned our troops accordingly, but the enemy is also adept at using the democratic space granted by our constitution to move around freely and unimpeded to sow terror," Lorenzana said in a statement.
An improvised explosive device tore through the bustling market in the heart of Davao city and close to one of its top hotels just before 11 pm (1500 GMT) on Friday. At least 14 were killed and another 67 were wounded in the explosion, police said. Sixteen of the injured were in critical condition, a local hospital director told reporters.
Duterte initially raised the possibility of drug lords carrying out Friday's attack as a way of fighting back against his crime war. More than 2,000 people have died in his unprecedented anti-crime crackdown, drawing widespread international condemnation over an apparent wave of extrajudicial killings.
Durian vendor Maribel Tabalwon, 34, told AFP chaos broke out after the blast. She helped rescue three victims but one of them, a woman seven months pregnant, eventually died.
"The blast was so loud the ground shook. She was crawling but she was lucky enough no one trampled her during the stampede. She was shaking and bleeding."
Davao is the biggest city in the southern region of Mindanao, with a population of about two million people. It is about 1,500 kilometres from the capital of Manila. The city is part of the southern region of Mindanao, where Islamic militants have waged a decades-long separatist insurgency that has claimed more than 120,000 lives.
Duterte had been mayor of Davao for most of the past two decades, before winning presidential elections in landslide elections in May. He is well known for bringing relative peace and order to Davao with hardline security policies, while also brokering deals with local Muslim and communist rebels.
In recent weeks, he has pursued peace talks with the two main Muslim rebel groups, which each has thousands of armed followers. Their leaders have said they want to broker a lasting peace. However the Abu Sayyaf, a much smaller and hardline group infamous for kidnapping foreigners to extract ransoms, has rejected Duterte's peace overtures.
In response, he deployed thousands of troops onto the small and remote island of Jolo to "destroy" the group.
The military reported 15 soldiers died in clashes on Monday, but also claimed that dozens of Abu Sayyaf gunmen had been killed.
On Saturday, Duterte declared a national "state of lawlessness", which his security adviser said gave the military extra powers to conduct law enforcement operations normally done only by the police.
While Davao has been regarded as relatively safer than the rest of Mindanao, the Abu Sayyaf and other Islamic militant groups have carried out deadly attacks there in the past.
In 2003, two bomb attacks blamed on Muslim rebels at Davao's airport and the city's port within a month of each other killed about 40 people.
(WION with inputs from AFP)