MANILA - Philippine authorities are verifying reports that an Abu Sayyaf sub-leader was recently spotted in Davao City, the hometown of President Rodrigo Duterte.

Defense Secretary Delfin Lorenzana on Thursday said he has already ordered the military to look into it after Malaysian media earlier reported ASG sub-leader Idang Susukan was seen in the southern Philippine city with Moro National Liberation Front founding chairman Nur Misuari.

The report said Susukan was in the city supposedly for fitting of a prosthetic arm. It added that he "surrendered" to Misuari sometime in April, and that Misuari is expected to meet with Duterte in the coming days.

"The (Armed Forces of the Philippines) has taken cognizance of the report," Philippine military spokesman Maj. Gen. Edgard Arevalo said in a statement.

According to Lorenzana, he has asked the AFP Eastern Mindanao Command verify said report, but they have yet to receive information about it.

Lorenzana echoed concerns about Susukan's movement within the city, considering that he was involved in several crimes including kidnapping and beheading of victims.

"I am awaiting the official report," said Lorenzana, who admitted that the military is still unaware why Susukan and Misuari are in Davao, especially since Susukan is wanted by the military.

Maj. Arvin Encinas, spokesman of the Zamboanga City-based Western Mindanao Command, said Susukan remains an enemy of the military.

He also said the government does not recognize Susukan's surrender to Misuari since the latter is not part of government.

"He did not surrender to us. Misuari is not the government...As far as WesMinCom is concerned, he is still an enemy," Encinas said of Susukan.

"His giving himself up to Mr. Misuari is not the surrender contemplated under the law and does not make him immune from arrest," Arevalo, for his part, said of the ranking ASG leader.

Arevalo said the military is ready to assist the local police once it proceeds to arrest Susukan.

Encinas, meanwhile, said he is not aware of any scheduled meeting between Duterte and Misuari in the coming days.

Misuari was former governor of the Autonomous Region in Muslim Mindanao, the region replaced by the Bangsamoro.

In 2013, he was charged for alleged involvement in the Zamboanga siege, an attack the MNLF launched allegedly over its exclusion from peace talks between the government and another Moro group.

The siege left some 200 dead, including police officers, soldiers, rebels, and civilians. Misuari was released on bail in 2016 and has since met with Duterte several times.