Hospital officials in northern Mali say at least two people are dead and 18 wounded after a protest in the town of Gao turned violent.

One protester, Attayoub Maiga, said demonstrators were marching peacefully Tuesday when police opened fire as they approached the town's central market near police headquarters.

There was no immediate comment from police. The Malian government had banned the demonstration of people opposed to a peace accord signed more than a year ago with various armed groups in the north.

Boubacar Maiga, an official at Gao's hospital, confirmed the two deaths.

Despite the peace accord, extremists have continued to mount attacks against Malian soldiers and U.N. peacekeepers.