JOLO, Philippines (AP) -- Philippine officials say more than 100 marines have left southern Sulu province, where they helped battle al-Qaida-linked Abu Sayyaf militants for years, to a western province to help reinforce the country's claims in disputed South China Sea territories.

Officials say a significant military force of about 5,000 will remain in Sulu to deal with lingering Abu Sayyaf threats.

Defense Secretary Voltaire Gazmin says the shift is part of a plan for the military to gradually shift from an anti-insurgency role to territorial defense.

Sulu Gov. Sakur Tan says the send-off on Wednesday for the marines at the Jolo pier was bittersweet because he has struck friendships with many of them.

At the same time, he said it's an indication that terrorist threats in his province have eased.

AP-WF-09-26-12 0854GMT