Haitian rebels said Tuesday that they would arrest Prime Minister Yvon Neptune, a close ally of former President Jean-Bertrand Aristide who had fled the country.

"We will arrest him," Paul Arcelin, a senior rebel leader, tolda cheering crowd at the army's headquarters. "Arrest Neptune, arrest Neptune," shouted his supporters.

Neptune is a top member of Aristide's Lavalas Family party and his former presidential spokesman.

The prime minister's whereabouts are not known. But US Marines,who entered the violence-torn country as part of a multinational force, guarded his office in the Haitian capital of Port-au-Prince following the arrest threat.

Neptune formally announced Aristide's departure Sunday, and he would be replaced by an independent prime minister under a power-sharing plan aimed to end the Haiti crisis.