GAO, Mali: Tuareg rebels are moving to exert their own authority over north Mali by issuing security passes for the region, officials and residents said on Friday, underscoring the challenge of unifying the West African state before planned elections.

Rebels from the pro-autonomy MNLA have been handing out the security documents, stamped in name of the Azawad Republic they proclaimed last year, to drivers of vehicles in and around their northern stronghold of Kidal.

The Tuaregs re-occupied the isolated northern town in January after Islamist rebels holding the town fled an offensive by French troops.

The MNLA had seized control of north Mali, which it calls Azawad, in an April 2012 uprising. It was quickly pushed aside by better-armed Islamist rebels, including al Qaeda's North African wing AQIM, sparking fears the region would become a launchpad for attacks on the West.

A two-month French-led campaign broke Islamist dominance of northern Mali, sweeping their forces into desert and mountain hideaways.

But, with Paris cooperating with the Tuaregs in the north, Mali's army has refrained from re-entering Kidal or the surrounding region.

In a sign of a parallel Tuareg administration being put in place, Kidal residents said the MNLA was issuing drivers with papers from their Internal Security Department, complete with a stamp reading "The Azawad State: Unity, Freedom, Security".

One document, seen by Reuters, specified the type of vehicle, plus the owner's name, telephone number and address.

"All vehicles within the territory controlled by the MNLA must have this document," said Moussa Ag Assarid, the rebels' representative in Europe told Reuters in Paris. "In this way we can differentiate between potential terrorists, drug traffickers and ordinary drivers."

Ag Assarid said the documents were being issued for security reasons after several suicide bombings in Kidal in recent weeks.

He said the MNLA would take responsibility for the security of the north until negotiations with the government clarified the status of the region.

Interim President Dioncounda Traore, installed after a military coup a year ago, has said he is willing to negotiate with the MNLA provided it drops its demand for independence. He has promised national elections by July 31.

The MNLA has since said it would accept autonomy within Mali but refused to put down its weapons ahead of any talks.

With Paris cooperating with the Tuaregs, the MNLA's control over Kidal remains a thorn in the relationship between France and Mali.

"No one understands what is going on in Kidal," said Haminy Belco Maiga, president of Kidal's regional council, told Reuters in the capital Bamako.

The MNLA's assertion of authority over the region has angered many Malians, who blame the Tuaregs for plunging their poor, landlocked nation into war.

"They are thieves," said truck driver Ilias Toure, who was handed a security pass by MNLA checkpoint guards when he returned to Kidal after several months. "We need to find a solution quickly."