Hardline Islamists occupying northern Mali went on the rampage in Timbuktu on Saturday, attacking shrines of Muslim saints and threatening to destroy every religious site in the fabled city.

Armed militants from the fundamentalist Ansar Dine group have already destroyed the ancient tomb of at least one revered Muslim figures on Saturday, just days after UNESCO named the city an endangered world heritage site.

"They have raped Timbuktu today. It is a crime," said a source close to a local imam after the onslaught began early Saturday.

Ansar Dine, one of the Islamist groups which seized control of the vast desert north of Mali in the chaotic aftermath of a March coup in Bamako, said no religious site would be safe in Timbuktu.

"Ansar Dine will today destroy every mausoleum in the city. All of them, without exception," spokesman Sanda Ould Boumama said through an interpreter from the city.

UNESCO put the World Heritage site, a cradle of Islamic learning known as the "City of 333 Saints", on its endangered list on Thursday because of the continued unrest in the north.

The Ansar Dine spokesman suggested Saturday's action was in retaliation for the UNESCO move.

"God is unique. All of this is haram (or forbidden in Islam). We are all Muslims. UNESCO is what?" he said, declaring that Ansar Dine was acting "in the name of God."

Witnesses in Timbuktu said the gangs had destroyed the mausoleum of a saint whose 15th century tomb was already desecrated in May by members of Al-Qaeda in the Islamic Magreb, one of the groups in control in the north.

"As I am speaking to you, Islamists from Ansar Dine have destroyed the mausoleum of Saint Sidi Mahmoud," one witness said.

"They are now in the process of destroying the mausoleum (of Sidi Moctar)," said a local journalist. "They have said they will destroy everything."

Islamic and tribal Tuareg groups took advantage of the March 22 military coup in Bamako to push government forces out of northern Mali, an area the size of France and Belgium, including the cities of Gao, Kidal and Timbuktu.

UNESCO, the world's main watchdog over the safety of some of history's greatest treasures and most threatened cultural exhibits, designated Timbuktu a heritage site in 1988.

Beyond its historic mosques, Timbuktu has 16 cemeteries and mausolea, according to the UNESCO website.

It is also home to nearly 100,000 ancient manuscripts, some dating back to the 12th century, preserved in family homes and private libraries under the care of religious scholars.

At its height in the 1500s, the city, a Niger River port at the edge of the Sahara 1,000 kilometres (600 miles) north of Bamako, was the key intersection for salt traders travelling from the north and gold traders from the south.

MUJAO Friday threatened countries who would join a military intervention force.

Mali has been gripped by chaos since disgruntled troops swarmed the capital Bamako in the south in March and ousted the elected president of what had been seen as one of Africa's model democracies.

In the ensuing weeks, Tuareg rebels and Islamist hardliners have taken over a stretch of northern Mali the size of Afghanistan.

The Islamists, also including Ansar Dine and Al-Qaeda in the Islamic Maghreb, have since imposed an austere version of sharia law in northern Mali, and they have fallen out with the Tuareg.

Leaders of the Economic Community of West African States, or ECOWAS, were meeting in Ivory Coast Friday in a bid to end the crisis. The grouping is considering sending a military force of 3,300 troops to Mali.

MUJAO warned that its branches "in several countries are ready to strike the interests of countries that intend to participate in the force of ECOWAS", spokesman Adnan Abu Walid Sahraoui said in a written message.

"The MUJAO is committed to providing all kinds of material and military support for young Muslims determined to raise the banner of Islam. The scene today is open" for jihadists, said the statement sent to a correspondent in the capital Bamako.

The West African leaders gathered Friday in Yamoussoukro meanwhile called on the UN Security Council to speed up the adoption of a resolution authorizing the regional force.

The force requires international support for such an operation, and logistics support from the United States and France.

A first draft was considered too imprecise by the UN Security Council, and ECOWAS is reviewing the proposal.

The heads of state meeting in the Ivorian capital renewed their "commitment to a peaceful settlement" but reiterated their decision to use armed intervention if necessary, according to the final statement.

The MUJAO, for its part, claimed responsibility on Friday for an attack in Algeria -- against the regional headquarters of the paramilitary police in the town of Ouargla in which one person was killed and three were wounded.

It said in a text message in Bamako that a young Algerian from the southern town of Ouargla had carried out the attack, using a Toyota 4x4 car with "almost 1,300 kilograms of explosives".

"The cells of the MUJAO branch in Algeria succeeded in carrying out a rapid punishment for the Algerian authorities," spokesman Sahraoui said.

The MUJAO spokesman said the group accused Algeria of encouraging Tuareg rebels to go to war with it, although the secular MNLA Tuaregs had three months ago fought together with the Islamists to take control of north Mali.

The Islamists chased the MNLA out of Gao in the northeast on Wednesday after vicious fighting that left at least 20 dead, witnesses said.

On Friday the Islamists were reinforced by jihadists who arrived from Algeria, various sources said.