BAMAKO, Mali — Mali's military claimed Friday that it has held control of a key town where Islamic extremists had battled forces for a week, though aid groups warned they were unable to reach the area to provide humanitarian assistance.

Meanwhile, the United Nations warned that some 700,000 civilians could be displaced by the fighting in Mali, where France launched a military intervention last week to oust the rebels from power in the north.

The French took action after the Islamist militants advanced from their stronghold in the vast, desert north toward the central Malian town of Konna.