“An unspeakable tragedy has unfolded in Minnesota – my good friend and colleague, Speaker Melissa Hortman and her husband Mark, were shot and killed early this morning in what appears to be a politically motivated assassination,” he told reporters.

“Our state lost a great leader,” he said.

Walz said that in a second attack, Senator John Hoffman and his wife, of Champlin, were shot multiple times, underwent surgery and that he was “cautiously optimistic” that they would survive “this assassination attempt”.

“This was an act of targeted political violence,” he said. “Peaceful discourse is the foundation of our democracy. We don’t settle our differences with violence or at gunpoint.”

Law enforcement authorities said the gunman was impersonating a police officer and escaped after exchanging fire with police who responded to the attacks.

A large-scale search for the suspect was underway, they said.