Al Qaeda-linked militants in the southern Philippines have threatened to kill two German hostages they have been holding since April unless Germany stops supporting U.S. action against Islamic State militants, the SITE monitoring service said.
Philippine security officials said on Wednesday that they were checking intelligence reports of the threats from the small but violent Abu Sayyaf group, which is also demanding a ransom of 250 million pesos ($5.6 million) for the captives' release.
A police official said they are still verifying the group's reported demands.
Abu Sayyaf rose to prominence in the early 2000s by kidnapping foreigners. It has links with al Qaeda, although analysts and Philippine security sources say it has lately been focused on kidnap-for-ransom and other criminal activities.
In the message, distributed via Twitter and other websites, the militants said they would "kill one of the two hostages" if their demands were not met within 15 days, according to SITE Intelligence Group, which tracks communications from Islamist groups.
One website published photos of the German hostages, and a message written in Arabic and Filipino that read: "The Abu Sayyaf group officiallly gives warning to the families of the hostages, the German government, and the Philippine government -- First, give us our demand of 250 million pesos before October 10, 2014. If not, we will behead one of our hostages. Second, the German government must stop helping America in carrying out killings against our Muslim brothers in Iraq and Shams (Syria, Jordan, Lebanon and Palestine), and our mujahideen brothers especiallys in Islamic State."
"A message attributed to the Philippines-based Abu Sayyaf group threatened that two German hostages will be killed unless it is paid a ransom and Germany stops its support to the United States against Islamic State (IS)," SITE reported.
The German embassy in Manila declined to comment.
The United States and its Arab allies bombed Islamic State targets inside Syria for the first time on Tuesday (September 23). The Sunni Muslim group has seized swathes of territory in civil war-torn Syria and Iraq, slaughtering prisoners and ordering Shi'ites and non-Muslims to convert or die.
Germany has ruled out taking part in air strikes, but did break a post-World War Two taboo on sending weapons to active conflict zones by agreeing to arm Kurdish fighters battling Islamic State fighters in northern Iraq.
A Philippine military intelligence source said he was aware of the threats to the German hostages from Abu Sayyaf, but doubted they would be carried out, predicting that the group would most likely negotiate a lower ransom.
According to media reports, the two Germans, a man and a woman, were seized at gunpoint from a yacht between Malaysian Borneo and the southern Philippines in April.
Abu Sayyaf has been blamed for beheadings, bombings and kidnappings for ransom. The group is also holding a Dutch, a Swiss, a Japanese and some Filipinos in the south of the mainly Roman Catholic state.
In 2001, Abu Sayyaf rebels in the southern island province of Basilan beheaded an American who had been taken captive from an island resort in Palawan province. Two other Americans were held for more than a year, and one was killed during a rescue operation. The other survived with minor wounds.
About 200 U.S. special forces troops have been deployed in the southern Philippines since 2002 to help train and advise local soldiers in fighting Islamist extremists.