About a hundred fighters from across North Africa have joined the ranks of an Al-Qaeda offshoot which now dominates northern Mali, a Malian defence ministry official said on Sunday.

"According to our figures, about 100 north Africans, essentially from Algeria, Tunisia and Libya, have joined the ranks of Al-Qaeda in the Islamic Maghreb," a Malian defence ministry official told AFP.

"AQIM is also looking to recruit Moroccans and Egyptians en masse, but has not succeeded," the official added.

Islamic militants and tribal Tuareg groups took advantage of a 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.

In Timbuktu on Saturday, local residents said members of AQIM, supported by the armed Islamist group Ansar Dine, destroyed the tomb of a Muslim saint.

Mali's transitional government expressed outrage over the desecration, calling it "an unspeakable act", in a statement read out on national television.