Jakarta: Four Indonesian sailors kidnapped by suspected Islamic militants in the strife-torn southern Philippines were released Wednesday, the second group of Indonesian hostages to be freed this month.
Gunmen abducted the sailors on the high seas off the east coast of Malaysia`s Sabah state on April 15, shooting and wounding another crew member.
Philippine Islamist group Abu Sayyaf was suspected of having carried out the kidnapping, the latest in a recent spree of abductions that saw them behead a Canadian hostage last month.
Indonesian President Joko Widodo announced in Jakarta that the men had been released and were in good health.
"The hostage release was successfully conducted due to good cooperation between the Indonesian government and the Philippines," he said.
Philippine Foreign Secretary Rene Almendras thanked the Indonesian government for the "very close coordination" that helped secure the release of the hostages, and said efforts were aided by a recent deal aimed at halting the surge in abductions.
Foreign ministers of Indonesia, Malaysia and the Philippines agreed last week to lauch joint patrols of a key waterway between their countries and to set up a hotline to communicate faster in emergencies and improve intelligence sharing.
The hostages were dropped off outside the house of local politician Abdusakur Tan on Jolo, a mountainous and jungle-clad island in the far south of the Philippines known to be an Abu Sayyaf stronghold.
Tan -- the governor of Sulu province, which includes Jolo - said members of a Muslim rebel group had helped negotiate the release.
The Indonesians` release was secured through "persuasion and joint efforts of the military and police, and the local and provincial government. No ransom was paid for the freedom of the Indonesians".
However, Abu Sayyaf does not normally release hostages without a ransom.
The Philippine military said the freed Indonesians were taken to a military base for medical check-ups.
"Arrangements are now being finalised for the handover of the Indonesian nationals to Indonesian authorities," it added in a statement.
The group were abducted from a tugboat carrying coal that was sailing from Cebu in the Philippines back to Tarakan in Indonesian Borneo. Six other seamen, including the wounded man, managed to escape.
On May 1, 10 Indonesian sailors kidnapped five weeks earlier were also released on Jolo, and told harrowing tales about how the militants threatened to slit their throats.
Abu Sayyaf is a radical offshoot of a Muslim separatist insurgency in the south of the mainly Catholic Philippines. Its leaders have pledged allegiance to the Islamic State group, but analysts say they are more focused on kidnappings for ransom than setting up a caliphate.
They are still holding at least seven other foreign hostages -- four Malaysians, a Canadian tourist, a Norwegian resort owner and a Dutch birdwatcher.