Photo by Vina Araneta, ABS-CBN News

A memorial marker was unveiled on Tuesday in Davao City, where a huge explosion rocked a busy night market 40 days ago.

The memorial, with a bougainvillea plant standing in the middle of it, has been named "Tree of Life."

A plaque bearing the names of the fatalities is placed at its foot.

Davao City Mayor Sara Duterte unveiled the marker.

Photo by Vina Araneta, ABS-CBN News

Terror group Abu Sayyaf earlier claimed responsibility for the attack, but three members of the notorious Maute group were arrested for supposedly masterminding the blast.

They were presented to the media Friday afternoon.

Duterte heralded the arrest, saying it is just the beginning of the resolution of the incident.

"This development is commendable as we vow to expeditiously give justice to the 15 victims who died and the 69 others who were wounded in the blast," she said.

"We also need to remember that this does not end our desire to give justice to the victims and those whose lives were forever changed by that horrendous act of terrorism on the night of September 2 in our beloved city," she added.