Islamist rebels who have seized control of northern Mali used axes, shovels and automatic weapons to destroy tombs and other cultural and religious monuments for a third day on Monday, including bashing in the door of a 15th century mosque in Timbuktu, news agencies reported.

Rebels of the Ansar Dine faction fighting to assert Sharia law over the African nation at the crossroads of ancient trade routes ignored the appeals of United Nations officials over the weekend to cease the "wanton destruction" of the region's cultural heritage.

In New York, U.N. Secretary-General Ban Ki-moon on Sunday called on "all parties to exercise their responsibility to preserve the cultural heritage of Mali," saying the attacks "are totally unjustified."

Irina Bokova, head of the United Nations Educational, Scientific and Cultural Organization, on Saturday urged the Ansar Dine fighters "to stop these terrible and irreversible acts" after militants smashed mud-walled tombs in Timbuktu.

On Monday, the Islamists, who claim allegiance to Al Qaeda, tore open the door to the Sidi Yahia mosque, telling townspeople they were wiping out "idolatry" at the monuments to Sufi Islamic saints and scholars.

"In legend, it is said that the main gate of Sidi Yahia mosque will not be opened until the last day [of the world]," said the town imam, Alpha Abdoulahi, according to Reuters news agency, which reached him in Timbuktu by telephone.

In radio and television interviews from Senegal, the newly appointed chief prosecutor of the International Criminal Court, Fatou Bensouda, warned the rebels that destruction of religious and cultural heritage could lead to war crimes charges.

"The only tribunal we recognize is the divine court of Sharia," the Associated Press quoted Ansar Dine spokesmen Oumar Ould Hamaha as saying in response to Bensouda's warning.

The AP said Hamaha justified the destruction as a divine order to pull down idolatrous constructions "so that future generations don't get confused, and start venerating the saints as if they are God."

Timbuktu had been developed as a tourist attraction, with locals operating hotels, guest houses and guided tours for visitors to the ancient sub-Saharan trading post and Islamic educational center.

Hamaha told the AP that Ansar Dine opposes tourists' coming to the religious sites, saying they "foster debauchery."

UNESCO put Timbuktu and the nearby Tomb of Askia on its List of World Heritage in Danger last week, after the Ansar Dine rebels seized the region that has been beset by a three-way civil war since a March 22 coup deposed Mali's government. The Islamist radicals have been fighting for territory with Taureg separatists since the latter defeated Mali government troops in the spring, leaving the capital Bamako rudderless and incapable of putting down either rebellion in the remote north.

"Timbuktu was an intellectual and spiritual capital and a center for the propagation of Islam throughout Africa in the 15th and 16th centuries," UNESCO notes on its website. "Its three great mosques, Djingareyber, Sankore and Sidi Yahia, recall Timbuktu's golden age."

The sites designated as important cultural heritage represent "the power and riches of the empire that flourished in the 15th and 16th centuries through its control of the trans-Saharan trade," UNESCO recalls in its description.

Fundamentalist Salafist Muslims have also attacked Sufi heritage sites in Libya and Egypt over the past year, and Al Qaeda-allied Taliban militants a decade ago blew up two 6th Century Buddha figures carved into a mountainside near Bamiyan, in central Afghanistan, on the same grounds that they idolized false gods.

ALSO:

War crimes court staff accused of spying released in Libya

New 'green-on-blue' attack in Afghanistan kills 3 British troops

Wife of former Tunisian dictator apologizes, denies wrongdoing

-- Carol J. Williams in Los Angeles

Photo: A still from a video shows Islamist militants attacking a shrine in Timbuktu on Sunday. Credit: AFP / Getty Images