(CNN) -- Al Qaeda-linked rebels in northern Mali destroyed historic and religious landmarks in Timbuktu on Thursday, claiming the relics are idolatrous, residents told CNN.
Three four-wheel-drive trucks carrying at least 30 armed fighters arrived Thursday morning at three mausolea -- all U.N. World Heritage sites -- in the southern Timbuktu neighborhood of Kabara, two residents told CNN by phone.
"They started destroying the first mausoleum's wooden door with their axes," said Ibrahim Ag Mohamed, a guide. "Then they went inside and burned the cloth covering the grave before destroying the building with picks and axes."
The mausolea, one of which held the remains of a religious leader and the founder of the neighborhood, were destroyed within an hour, Ag Mohamed said.
"The local Islamists were reinforced by between 30-40 men carrying Kalashnikovs and axes," said Sankoum Sissoko, another resident. "They started destroying the mausolea and didn't finish until they had turned the tomb into rubble," he said.
Area residents, too afraid to try to stop the destruction, simply watched, he said. "After the attack, the Islamists told the people that worshiping saints is not right, according to their form of Islam, and the destruction was necessary," he continued.
Thursday's attack was at least the fourth this year on Timbukto's historic tombs, said Osmane Halle, the former mayor of Timbuktu.
International outrage has been growing over the destruction of the West African nation's shrines.
The United States and a number of other nations have condemned previous attacks on Mali's historic tombs.
Chaos has rocked the country since March, when a military ruler overthrew the democratically elected president, shaking what had been one of West Africa's most stable democracies.
The coup leader stepped down in May and transferred power to a civilian transitional government, but uncertainty looms.
Ethnic Tuareg rebels and other Islamist militants have taken advantage of the uncertainty to seize control of the northern portion of the country, including Timbuktu.
Ansar Dine, an al Qaeda-linked group claiming control of the city, is blamed for the attacks on historical landmarks.
The picturesque city, considered an important destination for Islamic scholars, features a number of ancient and prominent burial sites.
Islamist militants regard such shrines as idolatrous and thus prohibited by their religion. They have targeted Sufi shrines, which they say they are sacrilegious. Sufism is a mystical dimension of Islam considered offbeat by Islamic hardliners, who frown upon it. The Sufis, who took Islam to much of sub-Saharan Africa, dance, pray and preach using drama and humor.
"If the Islamists continue in this way, there will be nothing left of Timbuktu's sacred heritage that made it famous all over the world," Halle said. "I ask the international community to help Mali find a solution to the country's problem, no matter if it's a military intervention or negotiations, this has to end."
Last week, the U.N. Security Council approved a resolution that gave regional leaders until November 19 to provide plans for an international military intervention that would oust rebels from northern Mali.
The resolution, which passed by a unanimous vote, calls for retaking the region from al-Qaeda-linked rebels.
In a similar attack in 2001, the Taliban destroyed ancient Buddhist relics in Afghanistan.
Journalist Katarina Hoije in Bamako, Mali, contributed to this report