The grieving wife and siblings of a Malaysian hostage who was beheaded by Abu Sayyaf extremists in the southern Philippines have retrieved his remains in Manila.

Bernard Then was kidnapped with a compatriot, Thien Nyuk Fun, by the Abu Sayyaf in May in Malaysia's Sabah state and taken by boat to the southern Philippine province of Sulu. Thien was freed but Then was found beheaded.

Malaysian official Fatimah Abdullah, who flew to Manila to help the family carry home the remains, urged the public on Friday to help fight terrorism by educating their young to respect laws and value life.

Malaysian Prime Minister Najib Razak has condemned the brutal killing.

The small but violent group has been weakened by military offensives, but still finances itself largely by kidnappings and extortion.