MANILA, Philippines – The Bureau of Immigration (BI) is on heightened alert following the bombing in Jolo, Sulu, last Sunday, placing its personnel on the lookout for “suspected foreign terrorists.”

“I have instructed our Port Operations Division to alert all its personnel and be on the lookout for suspected foreign terrorists who might attempt to enter the country,” BI Commissioner Jaime Morente said in a statement on Tuesday, January 29.

Morente said that foreigners “who cannot satisfactorily explain their purpose in coming here are to be turned back and booked on the first available flight to their port of origin.”

Travel control and enforcement unit (TCEU) personnel have been ordered to conduct “secondary inspection” of passengers with “doubtful documents and travel purpose.”

The BI said this action was prompted by the statement of the Islamic State (ISIS) claiming responsibility for the bombing. (READ: What we know so far: Jolo Cathedral bombing)

Western Mindanao Command spokesman Lieutenant Colonel Gerry Besana said they are still “verifying everything.”

Authorities are still unable to identify two bodies from the blast site, but Besana said this does not necessarily bolster ISIS’ claim of suicide bombing.

“How would you identify whose body almost evaporated? Can’t it be a husband and wife who went together, both died and no relative knew they were there?” Besana asked. 

The two bomb attacks, which happened minutes apart, killed at least 23 and injured 109 people. The death toll rose as of February 4. (READ: 6 children among wounded in Jolo Cathedral bombing)

The Duterte adminstration is expected to use the Jolo bombing to justify its 3rd extension of martial law in Mindanao, which will be tackled in oral arguments at the Supreme Court at 2 pm on Tuesday. – Rappler.com