A state-sponsored witch-hunt has begun in Gambia where as many as 1000 people have been kidnapped from their villages and taken to "secret detention centres" then stripped, beaten and poisoned.

The campaign in the tiny West African nation is the latest manifestation of the increasingly brutal and bizarre rule of President Yahya Jammeh, who has claimed he can cure people of Aids. Now the President is thought to believe he is under attack from witches.

Witnesses and victims of the abductions told Amnesty International that the President's personal guard, with armed police and intelligence agents, accompanied witch doctors to round up suspects.

Many of those taken from their homes were elderly people who were held for up to five days in appalling conditions, made to drink hallucinogenic concoctions and forced to confess to black magic powers.

"At 5am, the paramilitary police armed with guns and shovels surrounded our village and threatened the villagers, saying anyone who tries to escape will be buried 6 feet under," one witness said.

"They randomly identified over 300 men and women who were forced at gunpoint into waiting buses and ferried to the President's home town."

Once there, the witness said they were stripped and forced to drink dirty water with unidentified herbs which caused diarrhoea and vomiting. Those who eventually confessed to being a witch were then beaten.

As a young Army lieutenant, Jammeh ended Gambia's post-independence experiment with democracy in a bloodless coup in 1994. Jammeh, 43, has since won three elections, all marred by widespread intimidation and the arbitrary jailing of his rivals.

He had his most prominent opponent, Halifa Sallah, imprisoned this month after he wrote a newspaper article condemning the activities of the witch doctors. The President is said to believe that witchcraft was responsible for the recent death of his aunt and responded by bringing in his own witch doctors from Guinea.

Jammeh caused an international stir two years ago when he tried curing Aids.

Dressed in a white West African garb and plastic surgical gloves, he rubbed a green paste into patients' bodies before making them swallow a "bitter yellow drink".

He insisted the cure could only work on Thursdays and required that patients immediately stop taking anti-retroviral drugs. A UN official who dared to question his Aids "cure" was thrown out of the country.

Last year, the President said homosexuals should be beheaded.

Even those close to him have begun to question his sanity and many former aides have fled after falling out with him.