Four persons of interest in Jolo attack surrender 

MANILA, Philippines (Update 1 8:50 p.m.) — Four people wanted in connection with the twin bombings of a Catholic church in Jolo, Sulu surrendered to authorities on Wednesday to clear their names.

WATCH: Suspected bomber flees Jolo cathedral

According to the Western Mindanao Command's Public Information Office, two persons of interest shown fleeing in a CCTV camera footage submitted themselves to the Sulu provincial police director on Wednesday morning.

The two were identified as Alshaber Arbi, 18, a high school student, who Westmincom said was the one in a ponytail in the CCTV camera footage, and Gerry Isnajil, a teacher, who in the video was wearing a maroon cap.

Two others also submitted themselves to authorities on Wednesday afternoon. They were identified as Alsimar Mohammad Albi, 24 and his 17-year-old companion. 

Alsimar and the 17-year-old were reportedly at a pharmacy nearby to buy medicine for the former's mother who was confined at the Integrated Provincial Health Office-Sulu Provincial Hospital when the explosion at the church happened. 

The latter two persons of interest said they do not know the two suspects from the CCTV camera footage. 

'Right decision to come out'

Sulu Provincial Police Director Senior Supt. Pablo Labra II said the persons of interest were questioned if they had connections to the Ajang Ajang group, a faction linked to the Abu Sayyaf terrorist group.

"Meron kasing mga sources of information who said that these people may be members of Ajang ajang," Labra told reporters Wednesday afternoon.

Although they are not yet considered suspects, Labra said it was a "right decision to come out." He added, "they also trust us, that's why they came to us and submitted themselves for questions."

Not ruling out possibility of suicide bomber

On Tuesday, President Rodrigo Duterte shared intel that the attacks were actually suicide bombings, carried out by a woman and her husband who blew themselves up.

Although police went after these suspects, Labra said that they are not ruling out that this could have been a suicide bombing.

"Ang access ng ating presidente ng sources of information ay malawak (the president's has wide access to information sources)," Labra said. 

"Di namin winawala ang possibility na ito'y kagagawan ng suicide bomber (We are not ruling out the possibility that this was the work of a suicide bomber)," he added. 

Sulu's top police chief said that they found evidence that might confirm the president's suspicion but cannot yet divulge the information.

"We're trying to piece together these pieces of evidence so we can come up with the real story," he said. 

At least 21 were killed and 100 others injured in the attacks. — Ryan Macasero