Four Rwandans have told the BBC the army forcibly recruited them to fight for the M23 rebel group in neighbouring eastern Democratic Republic of Congo.
The four said they were seeking asylum in Uganda after fleeing the fighting.
The Rwandan army dismissed their claim, saying they must have made up their stories to get asylum.
Last week, the US called on Rwanda to stop backing the M23. UN experts and DR Congo officials say Rwanda has been sending troops to support the rebels.