KOTA KINABALU: A picture of the four Malaysian hostages kidnapped by the Abu Sayyaf group has been posted on Facebook, presumably by the terrorist group themselves.

The four, all sailors, are all seen squatting, with one of them holding up a piece of paper with the name "Victor Troy" and the date "April 8, 2016" written on it.

The Facebook page is believed to have been set up recently by the Abu Sayyaf group.

The four Malaysians – Wong Teck Kang, 31; Wong Hung Sing, 34; Wong Teck Chii, 29, and Johnny Lau Jung Hien, 21, all from Sarawak – were grabbed from MV Masfive 6 tugboat off Pulau Ligatan on April 1 when returning to Tawau after delivering a timber cargo to Manila.

The kidnappers made contact with the hostages' family members on April 12 with demands for their release.

On April 14, the families met Sarawak Chief Minister Tan Sri Adenan Satem to ask for help.

It is still not clear which Abu Sayyaf group kidnapped the four, but it is believed they are being held by a certain sub-commander known as Sawajan.

People familiar with Abu Sayyaf kidnap-for-ransom operations say that the groups are linked and help each other to avoid Philippines military operations on the notorious southern Philippines island of Jolo.

They say the name used for the Facebook page was most likely fictitious, but it appeared to be an attempt at opening a mode of communication with victims' family members and others.