MANILA (Reuters) - A deadline set by Islamist militants in the southern Philippines to execute one of two German hostages passed on Friday with no word on the fate of the captives, although government sources in Berlin said negotiations for their release were under way.
The hostages, captured by Abu Sayyaf militants in April from a yacht on the high seas, are being held in the interior of the remote island of Jolo, 600 miles (960 km) south of Manila.
The Abu Sayyaf, which says it supports Islamic State fighters in the Middle East, had said it would execute one of the two at 3 p.m. (0800 BST) if a ransom of 250 million Philippine pesos (£3.46 million) was not paid. The militants have also demanded Germany stops supporting U.S.-led air strikes on Islamic State fighters in Iraq and Syria.
They later said they were willing to extend the deadline by two hours if they were assured the ransom was on its way.
A senior Philippine military officer in the region, Rear Admiral Reynaldo Yoma, said negotiations with the militant group were on, but he did not know of any details. He said any attempt at a rescue operation "might derail ongoing negotiations".
German government sources told Reuters that Foreign Minister Frank-Walter Steinmeier had sent a special envoy to the Philippines to negotiate a deal.
The envoy, Ruediger Koenig, had arrived in Manila, the sources said on Thursday evening.
The Abu Sayyaf, which has a record of kidnappings, killings and bombings, called a radio station in Zamboanga city to reiterate its demands as the Philippines stepped up army patrols on Jolo, a hotbed of Islamist militants in the mainly Catholic country.
"We are willing to extend the deadline for two hours if we get a call that ransom will be paid," Abu Rami, a spokesman for the Abu Sayyaf, told the Radio Mindanao Network in a telephone call. The group has used the radio station for its previous contacts with authorities.
The German man, who spoke briefly in the same call to the radio station, recalled how he and a female friend were taken hostage while on a holiday near the southern island of Palawan. He said life in the jungle was hard and it was taking a toll on his health.
Lieutenant General Rustico Guerrero, a Philippine military commander, said the government was closely monitoring the situation on the ground.
"We know the general area where they are. We are aware of the demands and situation but this all we can say. We don't want to put the lives of the hostages in jeopardy," Guerrero said.
It is not clear if the militants, who claim they want an independent Islamic nation in the south but are known for kidnap-for-ransom raids, have contacts with Islamic State.
Some Muslim groups in the southern Philippines have long been fighting Manila's rule, but Abu Sayyaf burst into prominence in 2000 after kidnapping 21 tourists and workers from a dive resort in nearby Malaysia.
They held the hostages, who included French, German, Finnish and South African nationals, for months on Jolo before freeing them for millions of dollars in ransom paid by then Libyan leader Muammar Gaddafi, according to Philippine officials.
Libya denied it paid a ransom but acknowledged government officials were involved in negotiations. Several of the hostages visited Tripoli after their release.
(Reporting by Manuel Mogato and Karen Lema in Manila and Michael Nienaber in Berlin; Writing by Karen Lema; Editing by Raju Gopalakrishnan adn Nick Macfie)