By Ainur Rohmah

TUABN, Indonesia

Family members of 10 Indonesians abducted off the southern Philippines last month expressed fear for the sailors’ lives as a ransom demand deadline fell on Friday.

Suspected members of the Daesh-linked Abu Sayyaf militant group are thought to have boarded an Indonesian vessel and kidnapped its crew at gunpoint in late March, before setting April 8 as the final date to pay a ransom of 50 million pesos ($1 million).

The father of one of the hostages, 29-year-old Wendi Rakhdian, was quoted by okezone.com Friday as saying that he hoped the ransom would be paid by Indonesia or the sailors’ employer.

"I worry that if a ransom to the Abu Sayyaf is not paid, then there will be a firefight between the army and the terrorists," said Aidil, who like many Indonesians uses one name.

He expressed concern that any clashes could endanger the lives of the captives.

The father of another captive had earlier expressed hope to Anadolu Agency that his son would soon be released.

"We continue to pray and pray that Bayu will be home soon," Sutomo said, adding that his oldest 22-year-old son may now have to postpone his wedding.

Cabinet Secretary Pramono Anung assured Friday that the government continues to monitor the progress of negotiations between suspected Abu Sayyaf members and Philippine authorities.

"President [Joko Widodo] is constantly monitoring the latest developments as the deadline is approaching," detik.com quoted him as saying.

Anung underlined that the Indonesian government is aware of the whereabouts of its citizen based off satellite images, and respects its neighboring country’s efforts to free the captives.

"We put forward the measures of fraternity and soft diplomacy," he stressed.

Manila had earlier refused Jakarta's offer of help in tracking down the kidnappers and recommended against payment of the ransom.

Indonesian Defense Minister Ryamizard Ryacudu reiterated that they are nonetheless ready to deploy troops if needed, with five warships and a number of elite navy troops on “standby position” in North Kalimantan province on the island of Borneo.

On Thursday, Foreign Minister Retno Marsudi said that information out of Manila indicated that the Indonesians are in good condition.

National news agency Antara also cited Coordinating Minister for Political, Legal and Security Affairs Luhut Binsar Panjaitan as saying that the company owning the commandeered vessel had expressed willingness to pay the ransom in exchange for the sailors’ release.

Since 1991, the Abu Sayyaf -- armed with mostly improvised explosive devices, mortars and automatic rifles -- has carried out bombings, kidnappings, assassinations and extortion in a self-determined fight for an independent Islamic province in the Philippines.

It is notorious for beheading victims after ransoms have failed to be paid for their release, many of whom have been kidnapped from the sea lanes and islands that lie between Indonesia, Malaysia and the southern Philippines.