Authorities suspect that Filipino illegal immigrants were involved in the recent kidnapping of Indonesian fisherman in Malaysia.

On September 11, two Indonesian fishermen were abducted by two armed men who boarded a fishing vessel anchored off Pulau Gaya in Semporna. The fishermen were taken to Talipao in Sulu province in the southern Philippines, Daily Express reported.

Eastern Sabah Security Command Chief Dato Hazani Ghazali said that it is believed the kidnappers were able to retrieve information from Filipino illegal immigrants who had been staying in Malaysia for a long time.

“The illegal immigrants are familiar with the activities of fishermen, especially on the east coast of Sabah,” Ghazali said.

Authorities believe that the kidnappers are members of the Abu Sayyaf group, which operates in waters near Malaysia and the Philippines and is made up of militants who have been active since the 1990s.

“The smaller groups snatch their victims and hand them over to the Abu Sayyaf. who make the ransom demand,” Ghazali said.

Read: Kidnapped Indonesian fishermen set free in the Philippines

Read: Three Indonesian fishermen kidnapped in Malaysia