MANILA - Interior and Local Government Secretary Mar Roxas on Monday said the military pushed the offensive against Moro National Liberation Front rebels due to an increased threat to the MNLF's hostages. Roxas said it is difficult to say how many hostages the rebels are still holding in Zamboanga City. Roxas said many of the hostages were able to escape yesterday. The hostages are now being debriefed by social workers and security forces. Authorities, however, are cautious as some of the MNLF captured by soldiers were pretending to be hostages.