"Beatrice, a Swiss national, was abducted this Sunday at Timbuktu by armed men," local official Mohamed Ould Hassen told AFP.
"I saw six armed men take Beatrice away this Sunday," said one resident of the town. "They shouted 'Allah Akbar' (God is great).
The sources described Beatrice as a Christian woman in her 40s, very active in the local community, who had lived for years in the city.
She was the last westerner still living there, having refused to leave after the Ansar Dine Islamist movement, with the help of Al-Qaeda in the Islamic Maghreb (AQIM), took control of the city on April 1st.
AQIM, which has bases in the north of Mali, operates in several countries in the region. It has abducted a number of Europeans in the past.