President Gloria Arroyo has placed the Armed Forces of the Philippines (AFP) and the Philippine National Police (PNP) on a "heightened state of alert" to prevent the entry of terrorists who were responsible for the destruction of the World Trade Centre in New York, the Pentagon and the bombing of the State Department in Washington D.C. on Tuesday morning.

"I have directed our Armed Forces and the Police to go on a heightened state of alert to secure all vital installations, utilities and infrastructure," Arroyo said in a statement.

The expected crackdown against Saudi Arabian billionaire, Osama bin Laden, might prompt the latter's supporters to go to the Philippines since many of them have established bases in Mindanao, southern Philippines, said Police Chief Director General Leandro Mendoza.

"Our main concern is the possible entry or influx of international terrorists into the country, and they might take advantage of the situation (in the U.S.). We know that Bin Laden's group has links with the extremist Abu Sayyaf in Mindanao," noted military spokesman, Brig. Gen. Edilberto Adan.

Brig. Gen. Adan detailed Bin Laden and his companions' deep connection with the hostage-taking Abu Sayyaf leaders who are based in Jolo and Basilan, in southern Mindanao. Abu Sayyaf founder, Abdurajak Janjalani, underwent combat training and scholastic studies in Afghanistan, with support from Bin Laden. He was killed by government troops in 1998.

Akim Murad, currently imprisoned in the U.S. for the World Trade Center bombing in 1993, was arrested in the Philippines in 1995 for allegedly plotting to assassinate Pope John Paul the second in 1995.

During his interrogation in the Philippines by Filipino and U.S. authorities, Murad had revealed that his group was planning to stage suicide attacks in the U.S., said Mendoza.

Ramzi Ahmad Youssef, who was convicted of terrorist charges in the U.S. for the 1993 World Trade bombing, also admitted he had visited Mindanao in early 1994 to establish cells to serve as contacts. He reportedly trained Abu Sayyaf members in modern explosive devices, said Mendoza.

At the same time, arrested terrorist Wali Khan Amin Shah had admitted that he had travelled to Mindanao to conduct training for the Abu Sayyaf Group, Mendoza claimed.

Bin Laden used his brother-in-law, Muhammad Jamal Khalifa, who stayed in the Philippines for several years until 1994, to establish Islamic non-government organisations and business networks. "These were used to facilitate the flow of funds for the MILF and the Abu Sayyaf," claimed Mendoza.

Bin Laden, now living in self-exile in Afghanistan, was also linked to the large Moro Islamic Liberation Front (MILF) which is currently holding peace talks with the government.

All these findings were retrieved from the intelligence file and submitted to the Federal Bureau of Investigation (FBI) to aid U.S. investigators and pin down those responsible for the series of attacks, said Mendoza.

The police have secured all foreign embassies in the country. A 3,000-strong military Task Force Libra has been placed on standby to provide support for police units in providing security for vital government installations, Mendoza confirmed.

In a letter of condolence to U.S. President George W. Bush, Arroyo said: "I join the whole world and our brothers and sisters in the U.S. in prayer. Let us pray that terrorism will end in the world."

Al Jacinto adds: The MILF, meanwhile, has condemned the series of terrorist attacks in the U.S. that has left a still undetermined number of people dead.

"This act of terrorism is highly condemnable and the MILF condemns whoever is behind it, or the perpetrators of these cowardly acts," said a regional MILF leader, Ustadz Shariff Julabbi.

At the same time, the MILF also branded as "terrorism" the U.S. missile attacks on Afghanistan.

"That is terrorism. The U.S. should investigate first if Bin Laden was really involved in the U.S. attacks before the Americans attack Afghanistan," Julabbi said.

"We are supporting the Palestinians' quest for freedom, just as the Muslims in the southern Philippines also quest for freedom and self-rule," Julabbi said.

The U.S. has denied the alleged retaliation against Bin Laden. Almost 90 per cent of Afghanistan is controlled by the Islamic militant group, Taliban, which have been protecting Bin Laden.

The latest terrorist attacks in the U.S. were believed to have been in retaliation for Washington's siding with Israel, which has carried out missile attacks on Palestinian targets over the past weeks that has left dozens of Muslims dead.

Israel has accused the Palestinian Hamas group as being behind a series of terrorist attacks in Israel.