Islamist forces in northern Mali have seized the town of Gao after clashes with Tuareg-led rebels.
At least 20 people have been killed and the political leader of the Tuareg-led movement has been wounded.
Residents say the Islamists linked to al-Qaeda took over buildings occupied by the Tuaregs in the town - including their headquarters.
Tension has been growing since the Tuaregs and Islamists jointly took control of northern Mali after a coup.
A spokesman for the Tuareg National Movement for the Liberation of Azawad (MNLA) told the BBC's Thomas Fessy that Bilal Ag Cherif was wounded during Tuesday's clashes.
His life is not in danger and he has been taken to a neighbouring country for treatment.
The fighting in Gao followed a day of protest after a local official was killed on Monday.
Residents said heavy weapons were being used.
A doctor in Gao told the BBC that most of the people who were killed and injured seemed to have been armed, but a number of civilians had also been caught in the fighting.
In March, the Islamists and MNLA advanced together through northern Mali after the government was overthrown.
Our correspondent says that they proved unable to reach an agreement after they took control of the region.
After weeks of an unlikely alliance between the Tuareg-led fighters seeking a secular independent north and Islamist rebels who want to impose Islamic Sharia law across northern Mali, this latest violence clearly illustrates the balance of power in the region, he adds.
More than 300,000 people have fled northern Mali since the rebels took the territory in the days following the 22 March coup.