BAMAKO: Militants fleeing Timbuktu in the face of a French-led offensive in Mali have torched a building housing ancient Arabic manuscripts, security and army sources said Monday.

“A building housing the manuscripts was burned,” a security source told AFP.

Timbuktu, which was the intellectual and spiritual capital of Islam in Africa in the 15th and 16th centuries, is renowned for its collection of manuscripts, some of which date back to the pre-Islamic era.

“The Islamists caused damages before leaving. They burned houses, and manuscripts,” said a source in a reconnaissance team which first reached Timbuktu on Sunday.

Malian and French troops surrounded the fabled city on Monday, after ten months of occupation by extremist militants who earlier destroyed ancient Muslim shrines they consider idolatrous.

Timbuktu mayor Halley Ousmane also confirmed the destruction of the building.

“I spoke to my media officer this morning. What has happened in Timbuktu is tragic,” he said.

“The Ahmed Baba centre, which holds valuable manuscripts, has been burned by the Islamists. It is a complete cultural crime.”

The Ahmed Baba Centre for Documentation and Research (CEDRAB) was founded in 1973 and has built up a collection of between 60,000 and 100,000 manuscripts, according to the Malian culture ministry.

In 2009 the new Ahmed Baba Centre was opened as part of a bilateral agreement with South Africa to promote the conservation, research and promotion of the manuscripts as African heritage.

French-led troops surrounded Timbuktu Monday on after seizing its airport in a lightning advance against the insurgents, who have been driven from key northern strongholds.

French paratroopers swooped in to block any fleeing militants while ground troops coming from the south seized the airport in the ancient city, which has been one of the bastions of the extremists controlling the north for 10 months.

“We control the airport at Timbuktu,” a senior officer with the Malian army told AFP. “We did not encounter any resistance.

”French army spokesman Colonel Thierry Burkhard told AFP the troops, backed up by helicopters, had seized control of the so-called Niger Loop, the area along the curve of the Niger River flowing between Timbuktu and Gao, in less than 48 hours.

“We will liberate Timbuktu very soon,” French Foreign Minister Laurent Fabius told France 2 television channel. “Little by little, Mali is being freed … This has been a very complicated operation but until now very well managed,” he said.

French warplanes had carried out some 20 air strikes Saturday and Sunday in the Gao and Timbuktu regions, a French ministry statement said.

Mali's lengthy crisis was kickstarted by a Tuareg rebellion for independence in January last year which overwhelmed the weak Malian army and prompted a coup in Bamako in March.

Amid the political vacuum the Tuareg desert nomads and religious extremists seized the north in a matter of days. But the extremists had no interest in the Tuareg desire for independence and quickly sidelined their erstwhile allies.

The occupation of an area twice the size of France sparked fears abroad that northern Mali could become a new haven for terror groups, threatening the West as well as neighbouring African countries.

However plans to intervene remained mired in hesitation.

In early January the militants broke through into the government-held south, raising fears that they could seize the capital Bamako and prompting intervention by former colonial power France.

There have been reports of reprisal attacks and the killing of Tuaregs, a Berber people, and Arabs leading the rebellion against Bamako by Malian soldiers and the local people.

“We have already witnessed reprisals... and thousands of people going into exile fearing for their lives,” said Corinne Dufka, a researcher from Human Rights Watch, urging immediate action from authorities to lower tensions.

African Union summit

At an African Union summit in Addis Ababa where leaders discussed increasing troop numbers for an African intervention force in Mali, outgoing chairman and Benin President Thomas Boni Yayi criticised the AU's slow response.

France's action, he said, was something “we should have done a long time ago to defend a member country”.

Defence chiefs from West African regional grouping ECOWAS agreed on Saturday to boost their troop pledges for Mali to 5,700. Chad, which is not a member of the 15-nation bloc, has promised an extra 2,000 soldiers.