* Veteran Algerian jihadist Belmokhtar claims Niger attacks
* Belmokhtar planned hostage taking at Algeria gas plant
* Niger attacks are 'shockwave' of Mali conflict
French special forces and Niger troops shot dead on Friday the last two Islamists involved in a twin attack on a military base and a French uranium mine in Niger claimed by the mastermind of January's mass hostage-taking in Algeria.
Mokhtar Belmokhtar, a one-eyed veteran of al Qaeda's North African operations, said in a statement that his Mulathameen brigade organised Thursday's raids with the MUJWA militant group in retaliation for Niger's role in a French-led war on Islamists in Mali.
The coordinated dawn attacks killed 24 soldiers and one civilian and damaged machinery at Areva's Somair mine in the remote town of Arlit, a key supplier of uranium to France's nuclear power programme. The attacks raised fears that Mali's conflict could spread to neighbouring West African states and brought an Islamist threat closer to France's economic interests.
Niger's government said French special forces had helped to end the resistance of two Islamists fighters who were holed up inside the army barracks in the desert town of Agadez early on Friday.
"Niger is more determined that ever to fight terrorism in all its forms," the government spokesman, Justice Minister Amadou Marou, told state television.
He said a total of 10 Islamists died in the attacks: eight in Agadez and two in Arlit. "The government reassures national and international opinion that every step is being taken to protect people and property across the whole of the country."
Two military cadets were killed by the cornered Islamists, the minister said. However, a military source, asking not to be identified, said the cadets were shot dead in Friday's raid.
French Defence Minister Jean-Yves Le Drian told BFM television that special forces had intervened at the request of Niger President Mahamadou Issoufou. France stationed special forces in northern Niger to help protect its desert uranium mines, which provide a fifth of the fuel for France's nuclear reactors.
Niger has emerged as a firm ally of France and the United States in the fight against al Qaeda-linked groups in the Sahel. It has deployed 650 troops in neighbouring Mali and sought to shut its porous desert borders to Islamist groups that are thought to have shifted their bases to southern Libya.
Belmokhtar, signing his statement with his pseudonym Khalid Abu al-Abbas, said the raids were a response to Issoufou's public claims that the Islamists had been defeated in Mali.
"We will have more operations by the strength and power of Allah and not only that, but we will move the battle to inside his country if he doesn't withdraw his mercenary army," the communique, whose authenticity could not be verified, said.
SHOCKWAVE FROM MALI
Belmokhtar's brigade claimed responsibility for January's attack on the In Amenas gas plant in southeastern Algeria in which 37 foreigners were killed, saying it was retaliation for the French-led campaign in Mali.
MUJWA and al Qaeda's North African wing AQIM have pledged to strike at French interests across the region after Paris launched the ground and air campaign in January that broke their 10-month grip over Mali's vast desert north.
Recent MUJWA suicide attacks around the northern city of Gao - where the group imposed harsh sharia law during a 10-month rule - have caused relatively little damage. Analysts said the strong impact of Thursday's attack appeared to reflect Belmokhtar's bold strategic thinking.
Belmokhtar has links with MUJWA, having spent time in GAO when it was controlled by the Islamist group last year.
"This attack is part of the shockwave from the war in Mali," said Yvan Guichaoua, an expert on Niger at University of East Anglia. "I am not surprised at all that it took place in Niger ... Militarily effective groups are fleeing Mali."
The MUJWA, which split off from AQIM in 2011, is a largely black African jihadi group with recruits from several West African countries which has claimed previous attacks outside Mali, including the kidnapping of aid workers in Algeria.
Chad's army claimed Belmokhtar was killed in northern Mali this year but Western intelligence services had played down reports of the veteran jihadist's death.
Mauritania's Alakhbar news website, which has contacts with Islamist groups, cited what it said was a spokesman for Belmokhtar's brigade saying the Niger raid was carried out by a mix of Islamist fighters from Sudan, Western Sahara and Mali.