By Abdoulaye Massalatchi
NIAMEY, April 8 (Reuters) - Toubou tribesmen in the extreme southeast of Niger said on Monday they had killed seven soldiers, appearing to open up a new front in a growing conflict between Saharan nomads and the government.
The Toubou-led Revolutionary Armed Forces of the Sahara (FARS) said it had also captured six more soldiers in fighting over the weekend in the region of Diffa, 1,400 km (870 miles) southeast of the capital Niamey.
Niger's army confirmed the clashes but said only two people had been killed, one on each side.
FARS said last week it was joining forces with the Niger Justice Movement (MNJ), a Tuareg-led insurgency which has killed at least 70 government soldiers since February last year in a campaign for greater economic and political autonomy.
"The justice and good governance that we want for our country, we want for all people in Niger, be they in the south or north, the east or west," FARS President Bocar Mohamed Sougouma said on the MNJ Web site.
Numerous light-skinned ethnic Tuareg, Arab and Toubou groups in Niger's northern and eastern deserts staged a joint uprising in the 1990s to demand greater independence from the country's black African-dominated government.
Some Tuareg groups accepted a 1995 peace deal but the Toubou FARS held out until 1997, when they were granted an amnesty. Former fighters have since accused the Niger government of failing to respect those accords.
Frustrations have boiled over again as the government encourages more foreign mining companies to invest in the northern Agadez province, home to one of the world's richest reserves of uranium.
Some nomads who feel economically marginalised despite the 1990s peace deals, which were meant to better integrate them, say only the government more than 1,000 km (620 miles) away in Niamey is benefiting from the investment.
Niger's government does not recognise the MNJ, dismissing the group as common bandits and drug traffickers and has so far refused to negotiate with them.
The region around Agadez has been awash with arms since the end of the 1990s rebellion and is criss-crossed with smuggling routes carrying everything from fake cigarettes to small arms and migrants, often with the complicity of the security forces.
A senior police commissioner and Interior Ministry official in Niamey, Abdoulaye Amadou, was detained this week and is being investigated for links to the rebellion, said the rebels and another senior police officer.
"Information has been established that he had contacts with armed bandits, without any official authorisation, and we have to clear all that up," the officer said, asking not to be named. (For facts on the Tuareg uprising in Niger and neighbouring Mali, please click on [ID:nL08714493]) (For full Reuters Africa coverage and to have your say on the top issues, visit: africa.reuters.com/ ) (Writing by Nick Tattersall, editing by Alistair Thomson and Mary Gabriel)