Philippines police on Thursday arrested three men suspected of links to al-Qaida terrorist network. They also seized a ton of explosives.
The police were acting on a tip from authorities in Singapore who recently broke up a terror ring there.
The arrests in the southern Philippine city of General Santos came as American troops began setting up camp less than 200 miles away to assist the Filipino military in combating an Islamic separatist band of kidnappers that has been holding two American hostages.
The three arrests and the discovery of buried weapons indicated that a terrorist network connected with al-Qaida has been operating secretly for some time in at least four countries in Southeast Asia: Singapore, Malaysia, Indonesia and now the Philippines.
About 650 U.S. troops, including 160 members of Special Forces units, are moving into the southern Philippines to train and assist soldiers in maneuvers aimed at destroying the elusive Abu Sayyaf guerrillas on the island of Basilan. Some allege that Abu Sayyaf also has links to al-Qaida, Osama bin Laden's terrorist group, but the evidence is murky.
The Filipino government has billed the joint military operation an "exercise" but acknowledges that it could last up to a year and that American military personnel could take part in combat despite a constitutional ban on foreign troops engaging in military activity.
Philippines President Gloria Macapagal Arroyo insisted this week that the role of U.S. troops in the war games is legal and that their assistance could help eliminate Abu Sayyaf.
"We might finally crush the Abu Sayyaf" during the exercises, she said. "I am willing to weather the criticism because we'll succeed in the end."
Abu Sayyaf has held U.S. missionaries Martin and Gracia Burnham hostage since May. The group also is holding Filipina nurse Deborah Yap.
Dozens of other hostages have been freed since last summer as the Philippines military chased the kidnappers through the jungle of Basilan and the nearby island of Jolo.
There was no indication whether the three suspects arrested Thursday on the island of Mindanao have any links to Abu Sayyaf or to other Islamic separatist groups that have long fought the government in the southern Philippines.