Ship hijacking
Abu Sayyaf, which operates from southern parts of the Philippines, is known for abductions and beheadings - file photo Antara Photo Agency/Reuters

The Philippines-based Islamist group Abu Sayyaf, which pledged allegiance to Islamic State (Isis), has hijacked an Indonesian vessel and taken the 10 crew members hostage. The Indonesian navy has confirmed the boat has been seized by the militants and the government said they have received a ransom demand from the captors.

The Indonesian foreign ministry said the proprietor of the hijacked tugboat received calls from Abu Sayyaf, which is notorious for its abductions, beheadings and bombings. The ransom amount is thought to be about 50m Philippine pesos (£760,000; $1.08m) but it is yet to be confirmed by officials.

"The pirates treat the hostage well. They asked for a ransom," Indonesia's State Intelligence Agency's (BIN) chief Sutiyoso was quoted as saying.

In a text message sent to multiple local media outlets, Basriana, a spokesperson for the Indonesian embassy in Manila also confirmed: "The latest news said it's true that an Indonesian-flagged vessel has been hijacked and its crewmen have been kidnapped."

The abduction of the vessel named TB Brahma 12 is thought to have taken place during the weekend and it is still unclear where exactly the boat was sailing at the time of the incident. The vessel, loaded with coal, had departed from the Trisakti port in the Indonesian province of South Kalimantan and was headed to the Philippines.

Abu Sayyaf is a hardline militant group, which is also linked to al-Qaeda, largely operating from the southern areas of the Philippines and remains a serious security threat to the Manila administration.