Why did terrorists carried out the attack in Mali? What are their demands?

Al-Mourabitoun and their allies, the Movement of Oneness and Jihad and Ansar Al-Din, have been heavily involved in northern Mali. In 2012, they took over most of that region known as Azawad including the three major cities of Timbuktu, Gao and Kidal.
In 2013, they were ejected from those cities through a French military air campaign. Meanwhile, the Malian army assisted by French troops retook the cities and took prisoners. Some of those arrested are still in Malian jails.
Al-Mourabitoun wants to free them by any means.
The other demand is a political one. They say they want the government to stop persecuting "their people in the north and in the centre". This is interesting because usually they refer to the north only as the area they mostly care about because its inhabitants are mostly fair-skinned Tuareg and Arabs who complain of racism, marginalisation and injustice.
Now the mention of the centre comes after members of the black African tribe of Fullan took up arms and began to fight against the government, allegedly in coordination with al-Qaeda-linked groups in Mali.
This can only complicate the situation for the regime in Bamako as even back ethnic ties are joining the rebellion against it.
Read complete details through the link below
http://www.aljazeera.com/blogs/africa/2015/11/mali-attack-explainer-151121175700449.html