BAMAKO (Reuters) - Unknown assailants killed several Niger soldiers near the border with Mali on Wednesday, according to two Niger officials, during an ambush in which Radio France International (RFI) said U.S. soldiers were also killed.


"What is confirmed is that there are the bodies of five Niger soldiers and others seem to be missing but I cannot say whether there were U.S. victims," said Namatta Abubacar, a local official for the region of Tillaberi in Niger.


A diplomatic source in Niger confirmed the ambush, saying that the attackers had come from Mali and had killed and injured several soldiers. Neither source could comment on whether any U.S. troops, who are stationed in the West African country at Agadez, had been killed.


Pentagon and U.S. Africa Command officials did not immediately respond to requests for comment.


RFI said earlier on Wednesday a counter-attack was underway.

African security forces backed by Western troops are stepping up efforts to counter jihadist groups forming part of a growing regional insurgency in the poor, sparsely populated deserts of the Sahel.

(Reporting by Cheick Amadou Diouara and John Irish; Writing by Emma Farge; Editing by Chris Reese and James Dalgleish)