French nuclear group Areva, the world's second-largest uranium producer whose mine in northern Niger was hit by a car bomb on Thursday, extracts more than a third of its mineral in the impoverished west African country.

Areva has been present in Niger for more than 40 years, operating two big mines near the northern town of Arlit through two affiliated companies -- Somair and Cominak -- which represent 37 percent of its total uranium production.

Somair, which is 64-percent owned by Areva and 36 percent by the state of Niger, produced 3,065 tonnes for the group in 2012.

Cominak, which is owned 34 percent by Areva, 31 percent by Niger, 25 percent by Japan's Ourd and 10 percent by Spain's Enusa, produced 512 tonnes.

The group's total production in Niger, at nearly 3,600 tonnes, trails output in Kazakhstan, where it mined 3,661 tonnes.

Output is set to increase in two years' time when Areva opens a third mine to tap the vast uranium deposit at Imouraren, 80 kilometres (50 miles) south of Arlit.

The mine's opening, originally planned for 2012, has been put off on several occasions, notably following unrest in the region.

Areva said Thursday's blast killed one and wounded 14 at its Somair subsidiary. The attack has been claimed by the MUJAO Islamist group as revenge for Niger's involvement in a French-led military offensive in neighbouring Mali.

Areva's operations in Niger have been targeted before by Islamist extremists.

In September 2010 Areva evacuated a large part of its expatriate workforce from Niger following the abduction by Al-Qaeda in the Islamic Maghreb (AQIM) of seven employees of the group and its sub-contractor Sogea-Satom, a subsidiary of the BTP Vinci, which works in the uranium mine in Arlit.

Three hostages -- a French woman, a Togolese and a Madagascan -- were freed in February 2011, but four employees -- one from Areva and three from Vinci -- are still being held.

The company's heavy presence in Niger has also given rise to tensions with the local authorities.

The Niger government has on many occasions called the partnership with Areva unbalanced, demanding more benefits for the local population more.

Areva said last month it had agreed to pay 35 million euros ($45 million) over three years to the country, partly to compensate for the delay in opening the giant mine at Imouraren, now set for mid-2015.

That mine, expected to become the second-biggest opencast uranium plant in the world, represents an investment of more than 1.2 billion euros. Areva holds 56 percent of the project, Niger 34 percent and South Korea's Kepco 10 percent.

Niger is the world's fourth biggest uranium producer after Kazakhstan, Canada and Australia.

Areva employs 2,700 people in Niger and estimates the workforce of its subcontractors there to number around 5,000.

Areva was the world's biggest producer of uranium in 2009 and 2010 before slipping to second place in 2011 and remaining there in 2012, producing 9,760 tonnes of uranium, behind Kazakhstan's Kazatomprom.

Areva's mining activities represented 14.6 percent of its 9.3- billion-euro turnover last year, which also included nuclear reactor activities and waste reprocessing.

The group had a total workforce of 46,500 people last year, over 60 percent of whom were based in France.