The whereabouts of two kidnapped French girls remained a mystery on Wednesday more than 36 hours after one of the world's most ruthless guerrilla groups announced the sisters had been freed in Lebanon.

Relatives of Marie-Laure Valente, 7, and her six-year-old sister Virginie waited for them to arrive in France after an official of the Fatah Revolutionary Council (FRC) led by Abu Nidal said in Beirut on Monday they would be in Paris within hours.FRC spokesman Walid Khaled said the girls - seized on a yacht in the Mediterranean in November last year - had been freed following an appeal by Libyan leader Muammar Gaddafi, who backs the group.

But Khaled said on Tuesday Abu Nidal had visited the sisters at a "secret post" to wish them a safe trip. Later he was quoted by Christian Radio Free Lebanon as saying they were still at an FRC base in Lebanon.

"He refused to disclose the date of their release," said the radio, monitored by the British Broadcasting Corporation.

Earlier on Tuesday relatives had been placed on alert amid confused reports that the children were due to be flown to military airports in Corsica, the south of France, or the outskirts of Paris.

French television reported in its evening bulletin that an Interior Ministry official had telephoned the girls' uncle Andre Metral asking him to be ready to meet them at short notice. The Ministry was not available to comment on the report.

Political analysts said the FRC group appeared to be playing a cat-and-mouse game, deliberately building up the suspense to extract as much publicity as possible from the girls' eventual release.