SINGAPORE: The Philippines defence chief said Monday that 25 hostages are still being held by militants in the southern Philippines but urged that no ransom be paid for their release. Delfin Lorenzana also told a security forum in Singapore that President Rodrigo Duterte has been under pressure to declare martial law in at least three southern islands where jihadists operate, but he did not think there was a need. The defence secretary (minister) said the companies which employed two recently freed Indonesians had paid a ransom of 20 million pesos ($400,000). He did not identify the captives but the Philippine military said two Indonesian hostages were freed last month by militants from Abu Sayyaf, which has pledged allegiance to the Islamic State group. The two were among seven crew seized from a tugboat off the southern Philippines in June. Security analysts had said ransom was paid for the release by the Abu Sayyaf last year of a Norwegian hostage, although the Philippine and Norwegian governments denied it. Lorenzana told the Fullerton Forum organised by the International Institute for Strategic Studies that 25 kidnap victims are still being kept in the southern island of Jolo. Jolo is a stronghold of the Abu Sayyaf, which is known to behead its victims if ransoms are not paid. The group decapitated a Malaysian in 2015 year and two Canadians last year. Lorenzana said the army’s chief difficult in hunting militants was the presence of civilians in communities where they operate, who also benefit from the ransom money.