( CNN ) -- Authorities in the Philippines say they have stepped up security measures for a huge religious procession taking place in Manila on Monday after receiving information suggesting it may be the target of a terrorist attack . `` We have serious threats from trustworthy and credible information sources that the Feast of the Black Nazarene will be attacked , '' Cesar Garcia , a presidential national security adviser , said Monday . `` We are told that almost nine suspected terrorists from Mindanao , southern Philippines , are already in the capital and can carry out the attack . '' The Feast of the Black Nazarene is an annual Catholic festival in the Philippines during which millions of devotees join a procession centered around a wooden statue of Jesus Christ . President Benigno Aquino said Sunday that he had ordered law enforcement agencies , including the military , to ramp up security efforts around the procession , according to the official Philippines News Agency ( PNA ) . `` I call on our fellow citizens to exercise the maximum vigilance and discipline leading up to , and during , the procession , '' the news agency cited Aquino as saying . Mindanao is a predominantly Muslim autonomous region , which was set up in the 1990s to quell armed uprisings by people seeking an independent Muslim homeland in the Philippines , a predominantly Christian country . CNN 's Aliza Kassim contributed to this report .
The government has received 'serious threats , ' a presidential adviser says . The annual Catholic festival draws millions of devotees . The president orders security forces to step up measures . The threat is said to come from a Muslim autonomous region of the country .