Updated

The West African state of Mali is suffering its worst crisis in half a century after a coup in the capital and a rebel takeover in the country's north, an international human rights group said in a report released Wednesday.

Amnesty International documents a host of human rights abuses committed in the country including summary executions, arbitrary detentions and sexual assaults including rape. The rights group says that all parties to the conflict are believed to be responsible for human rights violations.

The north of Mali was taken over by a mix of Tuareg separatist forces and Islamist fighters in late March. Government forces, left in disarray after a coup in Bamako just a week before, fled the north without putting up resistance. In a matter of days, the Islamist fighters had seized control of the three largest towns in the north, including fabled Timbuktu, and have since attempted to impose Shariah law.

"The entire north of the country has been taken over by armed groups who are running riot," Gaetan Mootoo, Amnesty International's West Africa researcher said. "Tens of thousands of people have fled the region, creating a humanitarian crisis in southern Mali and in neighboring countries."

Amnesty says the humanitarian catastrophe that has been unleashed by the twin events is the worst the country has suffered since independence from France, five decades ago.

Among the testimony collected by the rights group is that of a young woman from the northern city of Gao who says she and others were raped by Tuareg fighters. Amnesty says these fighters are believed to be members of the Tuareg separatist group, the National Movement for the Liberation of the Azawad, or NMLA.

A spokesman for the group rejected Amnesty's claims.

"We have carried out our own investigations here in Gao and we have found no proof that our fighters have carried out such acts," Moussa Ag Acharatoumane told The Associated Press by telephone from Gao.

Meanwhile, Amnesty also says that Malian government soldiers beat and then executed three unarmed people accused of spying for the NMLA in the town of Sevare on April 18.

No one from the Malian government was immediately available to comment on the case.

Amnesty also said that in the north members of the Islamist group Ansar Dine are pressuring people through violence, including killings and intimidation, to change their behavior in accordance with a fundamentalist interpretation of Islam. Amnesty says a man accused of having consumed alcohol was whipped with a stick 40 times in Gao at the beginning of April.

"We are following Shariah law," said Sanda Ould Boumama, a spokesman for Ansar Dine. "And we have never killed anyone who wasn't armed. ... I think we simply have a different interpretation of human rights," he added.