Rebels in the historic Malian town of Timbuktu torched a library housing a collection of ancient manuscripts and other buildings as French and Malian forces closed in on one of their last strongholds, Timbuktu’s mayor said on Monday.

“They burned the Ahmed Baba Institute. It’s a catastrophe -- for Timbuktu and all humanity,” Timbuktu’s Mayor Halle Ousmane Cisse told dpa by telephone from Mali’s capital Bamako.

The news of the attack emerged as French and government forces took control of Timbuktu airport and other access points to the town.

French military spokesman Colonel Thierry Burkhard told DPA that French special forces had taken up position around the town Sunday night to “stop the terrorists escaping.” Mali’s presidency confirmed on Monday its forces were inside the UNESCO World Heritage Site town and were conducting sweeps of the area.

Mr. Burkhard said France hoped to avoid combat inside the town of fragile mud-brick homes and ancient mud-and-timber mosques.

“The main idea is to avoid all senseless destruction of heritage as we have seen previously from the terrorists,” he said.

It was already too late for the Ahmed Baba Institute, which housed over 20,000 precious manuscripts on subjects ranging from medicine, astronomy and midwifery -- one dating back to the 13th century.

Cisse said the al-Qaeda-affiliated rebels, who had occupied the library months ago, set fire to the building “about three days ago,” as French and Malian forces were pushing north. A municipal official who witnessed the attack and then fled the town informed the mayor.

The rebels also torched the townhall and the home of a Timbuktu politician and shot dead a youth who showed his joy at the arrival of the forces by shouting “Long live France,” Cisse told DPA.

The attack on the library -- one of the largest collections of manuscripts that were passed down through Timbuktu families for generations -- deals another blow to Mali’s heritage.

Last year, the rebels caused an outcry by destroying shrines and tombs that they considered idolatrous. They also banned music and imposed amputations and floggings for crimes and so-called moral offences.

Malians have cheered as French warplanes bomb their positions and lead government forces in recapturing the towns, without much resistance.

Timbuktu is the second of the rebels’ three northern strongholds that government forces have entered within two days.

On Saturday, the French and Malian forces seized the northeastern town of Gao.

French planes also attacked the rebels’ last stronghold of Kidal, near Algeria at the weekend, in anticipation of a ground offensive there.

The war began on January 11, when France answered a call from interim President Dioncounda Traore for help to fight back the rebels after they headed south towards the capital Bamako.

The speed of the developments has blindsided the West African bloc ECOWAS, which had planned to help free northern Mali but whose troops have now been relegated to securing already liberated territory.

Analysts say that while France has outgunned the rebels in urban areas, gaining control over the desert hinterland, to which they have retreated, will be far more difficult.

Human rights groups are also warning of the risk of reprisal attacks by Malian forces against northern Mali’s nomadic Tuareg population, some of whom initially fought alongside the Islamists.

New York-based rights group Human Rights Watch warned of “dangerously high levels of ethnic tension” and called on Malian authorities to take “immediate, concrete, and unequivocal steps” reestablish the rule of law.

Italy, meanwhile, withdrew an offer to support France’s military mission in Mali after Prime Minister Mario Monti failed to secure support from the country’s main political parties.