MANILA, Philippines (AP) — Suspected Islamic militants detonated a powerful bomb that killed at least three people and wounded 27 others in a budget hotel packed with wedding guests in the southern Philippines, officials said Monday.

Investigators believe the blast and ensuing fire that gutted the two-story Atilano Pension House in downtown Zamboanga City late Sunday was a terrorist strike and that it was not linked to the wedding, city police director Edwin de Ocampo said.

Still, many of the victims were from a group of more than 20 people who occupied six of the hotel’s 35 rooms for a planned ceremony Monday. The tragedy forced the wedding to be postponed, Zamboanga Mayor Celso Lobregat said.

“We should not show that we’re panicking because that is what these troublemakers relish to see,” Lobregat told The Associated Press by telephone. “We have good leads. We will get all of them.”

The blast was believed to be one of two simultaneous bombings planned by al-Qaida-linked Abu Sayyaff militants. The other would have been on nearby Basilan island, where two explosives were separately found and safely defused by authorities in Isabela city on Sunday, de Ocampo said.

The hotel blast, caused by about 22 pounds (10 kilograms) of TNT powder, was one of the most high-profile bombings this year blamed on the Abu Sayyaf, which has been weakened by years of battle setbacks.