PARIS: A fifth French soldier was killed in the nine-week-old military campaign against Islamist rebels in Mali, the French government said on Sunday.

The corporal from the 1st Marine infantry regiment of Angouleme was killed in action, President Francois Hollande's office said in a statement, without giving details.

Dozens of Islamist fighters linked to al Qaeda have been killed as French and African forces have fought to drive them out of the northern region of Mali they have controlled since last April.

France launched a ground and air operation in January to break the Islamist rebels' hold on the region, saying militants posed a risk to the security of West Africa and Europe.

The offensive has wrested northern Mali from Islamist occupation and killed scores of fighters. Other rebels have retreated into mountain caves and desert hideaways stockpiled with arms and supplies.

The military operation is in its "final, most delicate stage," Hollande's office said.

The United Nations is considering setting up a 10,000-strong force in the former French colony before presidential and legislative elections in July, a deadline a European diplomat described on Tuesday as "a race against time".