By John Irish
PARIS (Reuters) - French forces destroyed a convoy in Niger transporting weapons from Libya to Mali and captured fighters linked to al Qaeda, the presidency said on Friday as France steps up efforts to stop militants crisscrossing the Sahel-Sahara region.
Paris, which has led efforts to push back Islamist fighters in the region since intervening in its former colony Mali last year, started redeploying troops across West Africa in July to form a counter-terrorism force, leaving U.N. peacekeepers to deploy across Mali's north to secure the country.
However, there has been a marked increase in attacks in recent months in the north, culminating on Tuesday in the death of a Senegalese U.N. peacekeeper being killed after a joint French-U.N. military camp in the northern Malian town of Kidal was hit by rocket fire.
"At a time when in Algiers negotiations for a peace deal and a lasting reconciliation in Mali are about to re-start, the armed terrorists ... are threatening peace and security in the entire region," the French president's office said in a statement, referring to talks between the Malian government and Tuareg separatists that are due to take place on Oct. 17.
"That is why the president has asked French forces to hunt down the armed terrorist groups behind these attacks."
The statement said that on Thursday night French forces, with support from Niger, intercepted and destroyed a convoy of armed vehicles in northern Niger belonging to al Qaeda's North African arm AQIM that were transporting weapons from Libya to Mali.
It is the first time Paris has announced such an operation in Niger.
"The intervention enabled a large quantity of weapons to be seized and to neutralise a number of those in the convoy, including some who were captured," the statement said, without giving further details.
Mali's prime minister told Reuters on Monday Islamist fighters had been given the opportunity to return to the north of the country after France redeployed its troops and urged French and U.N. forces to go on the attack to stop their resurgence.
France is setting up a base in northern Niger as part of its new counter-terrorism operation.
About 3,000 French troops are now operating out of Mali, Burkina Faso, Niger and Chad -- countries straddling the vast arid Sahel band -- with the aim of stamping out Islamist fighters across the region.
The French operation, dubbed Barkhane after the name of a kind of sand dune formed by desert winds, has set up its headquarters in the Chadian capital N'Djamena, but also placed an outpost in northern Chad about 200 km from the Libyan border.
French officials have repeated for several months they are concerned by events in Libya, warning that the political void in the north is creating favourable conditions for al Qaeda-linked fighters to regroup in the barren south of the country.
Diplomatic sources estimate about 300 fighters linked to AQIM, including a splinter group formed by veteran Islamist commander Mokhtar Belmokhtar, are operating in southern Libya, a key point on smuggling and trafficking routes across the region.
(Editing by Alison Williams)