Abu Sayyaf gunmen kidnaps two more Indonesians; 4th incident in two weeks
Representational image of an Indonesian fishing boat Reuters

Two more Indonesians were kidnapped off Malaysia's Sabah by five suspected militants from the Abu Sayyaf Islamist group, Philippine security officials said.

Major Filemon Tan, a spokesman for the military's Western Mindanao Command, said in a report that the gunmen chased a Malaysia-registered fishing trawler and finally managed to board it at around 7.30 pm on Saturday off Kunak district in Sabah.

Saparuddin Kone, the captain of the boat, and a crewman named Sawal Maryam were taken hostage by the gunmen. In the last two weeks, this is the fourth case of abduction along the porous borders between Sabah and Sulu archipelago, which is located some 1,000 km south of the Philippines' capital Manila. A total of 11 people have been kidnapped in the latest incidents.

The Abu Sayyaf group, linked to the Islamic State in Iraq and Syria (ISIS), recently captured a German, two other Indonesians and six Vietnamese.

On November 6, the militants kidnapped a 70-year-old German sailor, Jurgen Kantner, from their yacht named Rockall, off Sulu forests and killed his wife, Sabine Merz. Later, the locals recovered the woman's naked body, with signs of sexual assault, from the yacht.

Hours before this abduction, the gunmen took two Indonesian fishing boat captains in captivity in the waters off Sandakan. Again, on November 11, the group kidnapped six Vietnamese sailors in Basilan and reportedly shot another sailor.

The militant group is fairly small with about 400 members, but it is known for kidnapping people and demanding millions of dollars in ransom. If they fail to receive the ransom on time, they have been seen beheading their hostages.

These latest kidnappings come as the Philippines, Indonesia and Malaysia prepare to hold joint military training in 2017 to combat terrorist groups including Abu Sayyaf around their waters.

Philippine President Rodrigo Duterte also allowed Indonesian and Malaysian forces to pursue the kidnappers into Philippine waters. Earlier, Duterte had threatened the Abu Sayyaf group that he would eat them "alive" as they were "beyond redemption."

According to the reports, 16 captives, including Kantner, a Dutchman, five Malaysians, two Indonesians and seven Filipinos are still in the militants' captivity.