MANILA, Philippines – Abu Sayyaf militants in the Philippines have freed four Malaysian sailors more than two months after they were abducted off Borneo island, an official said Wednesday.

Maj. Filemon Tan, a Philippine military spokesman in Zamboanga, said the four crew members were freed early Wednesday in Sulu and immediately taken by speedboat to Sandakan in Malaysia’s Sabah state on Borneo.

Another Philippine military source said a ransom was believed to have been paid, but Tan said he couldn’t confirm whether that was true. Media reports have said the Abu Sayyaf demanded 18 million ringgit ($4.5 million) for the release of the four men, who were kidnapped from their tugboat on April 1.

Sabah police declined to provide details.

In April, Abu Sayyaf militants beheaded a Canadian hostage after they failed to receive a large ransom by a deadline they had set. Three other people who were kidnapped with him last September — another Canadian, a Norwegian and a Filipino — are still being held.

More than a dozen foreign and Filipino hostages remain in the hands of the Abu Sayyaf, including a Dutch bird watcher who was kidnapped more than three years ago.

Both the United States and the Philippines have labeled the Abu Sayyaf a terrorist organization.

Indonesia, Malaysia and the Philippines agreed last month to boost maritime security following increased kidnappings at sea by suspected Abu Sayyaf militants.