MANILA, Aug. 19 (Xinhua) — Philippine immigration agents detained on Friday nearly 180 Indonesian nationals who allegedly tried to leave the Philippines using fake Philippine passports.

Antonette Mangrobang, a spokesman for the immigration bureau, told GMA News TV that the 173 Indonesians, who apparently arrived in the Philippines in batches during the past weeks, were intercepted as they were about to board a 12:30 a.m. flight for Madinah, Saudi Arabia to participate in the Hajj Pilgrimage.

She said five Filipinos, who are escorting the Indonesians, are also being quizzed to shed light on the issue.

"We are still looking into how the Indonesians were able to sneak into the country. We want to know their point of entry, for instance. It's a big challenge for us because we are still verifying their true identities," Magrobang said.

She said the bureau has already sought the help of the Indonesian Embassy in Manila to help identifying the Indonesians. "We have decided to detain them at our detention center in Bicutan for the meantime," she added.

She said the immigration agents seized the Philippine passports used by the Indonesians. Initial investigation  showed the Indonesians paid 6,000 to 10,000 U.S. dollars each to their Filipino contacts to obtain the fake Philippine travel documents.

Bureau of Immigration Commissioner Jaime Morente in a statement said agents discovered that the Indonesians could not speak Tagalog or any other Philippine dialects from Muslim Mindanao during the initial investigations, saying they only spoke English.

Morente said the immigration agents found out that the Indonesians were on their way to Saudi Arabia to participate in the pilgrimage that will take place Sept. 9 to 14. They apparently used the quota reserved for Filipino pilgrims by the Saudi government, as there were no more available Hajj slots for Indonesians.

He said the Indonesians arrived in the Philippines as tourists in the past few weeks.

Already, Morente said he has ordered the immediate filing of immigration charges against the Indonesians for misrepresenting themselves as Filipinos and for being undesirable aliens.