Libyan people with the Kingdom of Libya flags gather during celebrations for the liberation of Libya in Quiche, Benghazi October 23, 2011. REUTERS

A Nigerien soldier has been killed and four wounded during clashes between Niger's army and a group of cars traveling south from Libya, the country's Defence Minister Mahamadou Karidio said. It is not clear yet if the troops were part of Moammar Gaddafi's fleeing entourage or al-Qaeda linked militants in the region. However, the direction in which the heavily armed convoy was traveling is the same route that was used by Gaddafi intelligence chief.

Both Libyan national and ethnic Tuaregs were in the convoy, according to a source quoted by AP news agency. A cash of arms was seized, including rocket-propelled grenades and assault rifles, according to Karidio.

Security experts believe Al Qaeda could try to acquire weapons from Libya, often described as an "arms bazaar", and transport them across the ungoverned desert separating Libya from Niger and Mali. The corridor has reportedly been exploited by arm and drug trafficker for years.

AP reports that Gaddafi supply of surface-to-air missiles raises several concerns among military experts. Many of them have an infrared homing device which would allow a fighter to simply aim it in the general direction of a passing plane to take it down.

In September, Niger's government said another son of Col Gaddafi, Saadi, had crossed into Niger and had been given refuge in the capital, Niamey.

The US has pledged to help Libya's National Transitional Council to recover missing weapons, including surface-to-air missiles.

Last month, the National Movement for the Liberation of the Azawad rebel group - made up of ethnic Tuaregs - emerged in Mali.

It said it would absorb Tuareg fighters returning from Libya.

Col Gaddafi was a strong backer of Tuaregs in Niger and Mali, who claim they are marginalised by the governments of the two countries.