Islamist militants in the Philippines seized four Indonesians after attacking their tugboat in the militancy-infested southern region of the country.
Seven gunmen in a speed boat attacked two Indonesian flagged tugboats off the cost of Sitangkay island in Tawi-tawi, Reuters reported citing Philippine military sources.
The island is near the border with the Malaysian state of Sabah. It is a region where frequent attacks on slow moving vessels have been witnessed in recent years.
"We don't exactly know who took them but the only lawless group operating in that area is the Abu Sayyaf," Major Filemon Tan said.
Indonesia's foreign ministry confirmed four citizens were abducted by gunmen who accosted their vessels on the Philippine island.
A ministry statement said six crew members were left behind by the attackers, but one of them was shot.
Indonesian officials said the injured man was in stable condition adding that Malaysian police evacuated the wounded men to a hospital.
Earlier this month four Malaysians from Sarawwak were kidnapped by gunmen from the region.
In March, around 10 Indonesian sailors were kidnapped in waters off the southern Philippines. The waters from where the crew were kidnapped are known to be infested with Abu Sayyaf militants.
The Philippine army engaged the southern militants in a fierce encounter last week, killing as many as 28 rebels after a militant ambush killed 18 soldiers and wounded more than 50 on Basilan island.
Abu Sayyaf has set an April 25 deadline for the release of two Canadians and a Norwegian captives abducted six months ago and kept in the Jolo island. The militants have demanded 300 million pesos ($6.50 million) in ransom for each of the captives.
Who are Abu Sayyaf guerillas?
Abu Sayyaf translates into 'Bearer of the Sword'. It is an Islamic militant group founded in the early 1990s by a preacher who returned from the Afghan war.
Abu Sayyaf took shape as a splinter group of the Moro National Liberation Front MNLF).
The group was behind several bombings, hostage taking and kidnap for ransom throughout the 90s. They were behind the Manila bombings in 2005 and the bomb explosion outside the Philippine Congress in 2007 that killed a Congressman and three others.
In 2001 they kidnapped tourists from a resort and murdered three of the hostages later, including an American.
Abu Sayyaf's vision is the establishment of a pan-Islamic super-state in Southeast Asia. Their immediate goal is to set up an Islamic state in the western Mindanao and the Sulu Archipelago.