With ultra-fast boats, millions in ransom payments and sympathetic locals, pro-Daesh militants on lawless southern Philippines islands who beheaded a German hostage this week have re-emerged as one of the nation's top threats.
The Philippines is planning to bring in foreign maritime forces to help fight the Abu Sayyaf, after a kidnapping spree that has raised fears the waters around its island strongholds may descend into a Somalia-like haven for pirates.
Declarations by key leaders of the Abu Sayyaf, a loose network of militants backed by local criminals and corrupt officials, of allegiance to the Daesh group have further stoked alarm.
"The nation's problem, the biggest threat, I would say, in the coming years it would be terrorism. It's sure to come," President Rodrigo Duterte said recently.
In an interview with AFP in February, Defense Secretary Delfin Lorenzana listed the Abu Sayyaf and other "terrorist" groups that have pledged allegiance to Daesh as the Philippines' top internal security threat.
"We are trying to put more effort into suppressing the growth of ISIS in the south," Lorenzana said.
Over the past two years the Abu Sayyaf has been involved in kidnapping dozens of people in increasingly brazen attacks mostly on foreign cargo vessels, but also on coastal tourist resorts in the south and neighboring Malaysia.
Kantner's beheading
The militants on Monday posted a video online of them beheading Jurgen Gustav Kantner, a 70-year-old German sailor who was abducted from his yacht in southern Philippine waters three months earlier.
They killed him after a demand for a ransom of 30 million pesos ($600,000) was not met and the deadline lapsed over the weekend. The militants circulated a video earlier this month in which Kantner said he would be killed if ransom was not paid by 3 p.m. Sunday.
The brief video circulated Monday by the SITE Intelligence Group, which monitors extremist websites, shows Kantner sitting in a grassy clearing and saying "Now he kill me" shortly before a masked militant beheads him with a curved knife. A few gunmen mutter "Allahu Akbar," or "God is great," in the video that lasts a minute and 43 seconds.
The Philippine military confirmed that Kantner had been "mercilessly and inhumanly murdered."
"Our operations in the past several days and nights using all our resources were unrelenting. We lost some of our best men in the process, because we value the life of Mr. Kantner and that of the others who have fallen prey to this terrorist group," spokesman Col. Edgard Arevalo said in a statement.
An intelligence report seen by The Associated Press said an Abu Sayyaf militant, Moammar Askali, had wanted Kantner to be killed as announced but others wanted to wait out for a ransom payment.
President Rodrigo Duterte apologized on Tuesday for failing to save Kantner, but insisted ransoms should not be paid.
Addressing the German government and Kantner's family, Duterte said he was "very sorry" about his death and that the military had stepped up an offensive against the Abu Sayyaf in an effort to save him.
"We really tried our best. We have been there. The military operation has been going on for some time already but we have failed. That has to be admitted," Duterte told reporters.
"But it's a matter of policy that we do not surrender to the demands of paying ransom. It will just increase the numbers," he said, referring to the militants.
"If you give in and pay, there will be more victims and no end in sight," Duterte said.
The Abu Sayyaf has earned many millions of dollars in ransom payments, and rarely releases a hostage unless money is paid, according to security analysts.
Relatives and employers of hostages typically pay, rather than governments.
Duterte also repeated Tuesday his request for China to help patrol regional waters to stop more kidnappings, saying Beijing had not given him a response.
Duterte specified he would like China to patrol the Malacca Strait, one of the world's busiest shipping lanes between the Malaysian peninsula and Indonesia's Sumatra island.
In Germany, Chancellor Angela Merkel condemned "this abominable act, which shows once again how inhumane and without conscience these terrorists act," spokesman Steffen Seibert said in a statement. "We must all stand together to fight against them."
German Foreign Ministry spokesman Martin Schaefer would not give any details on possible negotiations with the kidnappers, including whether there was a ransom demand, citing government policy and saying that "public comment never helps in finding a solution" in such cases.
The Abu Sayyaf claimed in November that its gunmen had kidnapped Kantner and killed a woman sailing with him off neighboring Malaysia's Sabah state. Villagers later found a dead woman on a yacht with the German flag off Laparan Island in Sulu province in the southern Philippines, the military said.
Kantner and his partner, Sabine Merz, were taken hostage by Somali pirates in 2008 and later freed, officials said.
Pirates' haven
The Abu Sayyaf is holding 19 other foreigners on its remote southern island strongholds of Sulu and Basilan, according to the military.
Most of them are Vietnamese, Indonesian and Malaysia sailors abducted from cargo vessels in or near the Sulu and Celebes seas.
To counter, the Philippines has said it is looking to Chinese and American forces to help patrol waters in the area, which also includes a busy international shipping channel called the Sibutu Passage.
Separately, the Philippines is in talks with Malaysia and Indonesia for joint patrols.
In his interview with AFP, Lorenzana said the Philippine naval and coast guard vessels could do little to catch the pirates' boats, which travelled at speeds of more than 80 kilometers (50 miles) an hour.
"The Abu Sayyaf has better boats than us," Lorenzana said.
Turning points
The Abu Sayyaf's spike as a kidnapping threat can be traced back to two events in 2014, according to security analysts.
One was the winding back of a US military program to train Philippine forces on how to counter the Abu Sayyaf, and provide intelligence. The program saw a rotating force of about 600 troops stationed in the south.
It ended in June 2014 after local Islamic extremists had "largely devolved into disorganized groups", according to a US government statement at the time.
Previously the Abu Sayyaf was regarded as a much bigger threat. It was accused of involvement in the 2004 bombing of a ferry in Manila that killed more than 100 people and other deadly attacks, as well as high-profile kidnappings.
During the 12 years of the American presence the Abu Sayyaf's numbers were cut from more than 1,000 to about 300, according to Philippine military estimates then, and many of its top leaders were killed or detained.
"The departure of the US advisers led to a steady resurgence of the ASG (Abu Sayyaf) and eventually the emergence of two dozen IS-centric groups," Rohan Gunaratna, a Singapore-based regional terrorism expert, told AFP on Tuesday.
Also in 2014 the Abu Sayyaf had one of their biggest paydays ever, claiming to have secured the full ransom of more than $5 million dollars for releasing two German sailors kidnapped that year.
That, and subsequent paydays worth hundreds of thousands of dollars, enabled the kidnappers to buy better weapons and boats, as well as pay local Muslim communities that harbor and protect them, according to analysts.
"The community celebrates when there's delivery of ransom. They kill cows, goats in festivity," Rommel Banlaoi, chairman of the Philippine Institute for Peace, Violence and Terrorism Research in Manila, told AFP.
Banlaoi and other analysts said corrupt politicians and security forces were also involved, getting a share of payouts and ensuring the Abu Sayyaf survived military offensives.
"It's really organized crime," Banlaoi said.
