BANJUL • Gambia's exiled strongman Yahya Jammeh plundered millions of dollars in his final weeks in power, leaving state coffers "empty", according to an aide to new President Adama Barrow.

Mr Jammeh flew out of Gambia late on Saturday, ending 22 years at the helm of the small West African nation, and headed for Equatorial Guinea, where he is expected to settle with his family.

A West African military force entered Gambia on Sunday, greeted by cheers from residents. Its aim was to provide security and to allow Mr Barrow - who has been in neighbouring Senegal for more than a week - to return and take over the presidency, which he won in elections last year.

Following Mr Barrow's win on Dec 1, Mr Jammeh refused to step down, triggering weeks of uncertainty that almost ended in a full military intervention.

Critics have raised concerns over the wording of a statement issued by the United Nations, the Economic Community of West African States (Ecowas) and the African Union that seemed to offer Mr Jammeh comfortable guarantees for his future.

"No legislative measures" would be taken that would infringe the "dignity, security, safety and rights" of Mr Jammeh or his family, it said.

Mr Jammeh slunk off in an unmarked plane and opponents now accuse him of theft.

A Barrow aide, Mr Mai Fatty, said that the new administration had discovered that some US$11 million (S$15.6 million) was recently stolen.

"The coffers are largely empty," he said in the Senegalese capital of Dakar. "As we take over, the government of Gambia is in financial distress."

Mr Barrow is eager to return "as soon as possible", Mr Fatty said, warning, however, that "the state of security in Gambia is still fragile".

On Sunday, "additional forces crossed into Gambia to beef up the numbers already on the ground," Mr Barrow said, according to a statement read out by Mr Fatty.

The new administration wants Ecowas forces to stay, Mr Fatty said, adding that Mr Barrow was waiting for assurances of loyalty from security forces, including the police and the army.

Mr Jammeh personally controlled certain segments of the security forces, and his long tenure was marked by systematic rights abuses, including extrajudicial killings, torture and arbitrary detention.

The Senegalese general leading a joint force of troops from five African nations said that soldiers would "control strategic points to ensure the safety of the population and facilitate... Mr Barrow's assumption of his role".

AGENCE FRANCE-PRESSE