Mali crisis: Who are the key leaders to know about?

Armed violence has intensified in Mali since Saturday after an al-Qaeda-linked armed group, working with separatists, attacked several military bases and took control of the northern city of Kidal. The group, Jama'at Nusrat al-Islam wal-Muslimin, controls swaths of rural territory, especially in the north and central regions, and has active cells around the capital. Armed groups have announced that they are laying siege to Bamako, the capital city.