Speaking to IGIHE, one of Rwandan Diaspora leaders in Mozambique said the assassin found him alone in the shop, shot him dead and took the money.
"It happened Friday night. It is shocking to hear such death of a young man who came to make ends meet" he said.
He said that the Rwandan diasporas are organising his burial in Mozambique, and will support his family.
Vincent Karega, the Rwandan envoy accredited to the southern African country said that the Police are investigating the case.
"He (Niyongira) was a finance manager at a shop of his fellow Rwandan. He was shot around 9:00pm and they took the money. Police suspect one person and are conducting more investigations," he said.