The al-Qaeda trained terrorists arrived in two groups on Oct. 18 and 21 from Madarash in Pakistan via Thailand where they took a Thai International Airlines flight from Bangkok.
Intelligence sources said Philippine authorities were provided the information by the United States Central Intelligence Agency (CIA) on the background and scheduled arrival of the ten Filipino-Muslims.
Airport authorities have monitored four of them directly proceeding to the Muslim communities in Quiapo in Manila and Quezon City while the others flew to Zamboanga City. Their identities were withheld for security reasons.
The CIA alert advisory confirmed an earlier disclosure by Immigration Commissioner Andrea Domingo that some Filipinos have received training financed by the terror network of Osama bin Laden.
Domingo also disclosed some Filipinos occupy key positions in Jemaah Islamiyah, a Muslim group with links to al-Qaeda operating in Southeast Asia.
The US intelligence community has issued a warning on the possibility of more terror attacks in the country similar to the Bali bombing in Indonesia
The Jemaah Islamiyah has been blamed for the Bali attack which killed almost 200 and left scores seriously injured, mostly foreigners.