has active links with Jemaah Islamiyah, the Southeast Asian conduit of Al Qaida.
Sources said if Usman had really been killed, then al-Qaeda ties with the Abu Sayaf
group could be proved.
Increased US involvement in the Philippines, where extremist Muslim separatist group Abu Sayaf
is fighting a guerrilla war, has heightened the concern.
It was supplied to the Indonesia-based Islamic Moro Front, which is linked to bin Laden and also to Abu Sayaf
, the terrorist group trying to establish a breakaway fundamentalist Muslim regime in the Philippines.