JAKARTA : An Indonesian hardline Muslim group held a mass prayer for slain terrorist leader Osama bin Laden on Wednesday night. Some 400 members of the Front Pembela Islam (FPI) or Islamic Defenders Front gathered at its Jakarta headquarters to offer prayers for Osama. Those who believe the Al-Qaeda leader is dead hailed him as a martyr. One of them said: "Maybe Osama is dead - we are grateful because he might become a martyr. And we believe so. We are hoping there'll be more Osamas that will emerge." However, others doubt Osama has been killed, citing the lack of evidence. Despite the heightened atmosphere, the two-hour-long event ended peacefully. The FPI are vigilantes who try to uphold Islamic laws through moral policing. They are known for smashing up bars in Jakarta that serve alcohol.