When Ross McGuiness heard strange noises outside his house on Friday afternoon, he never expected to come face-to-face with a gunman.

Forty-nine people have been killed in attacks on Christchurch mosques, with more seriously injured. Police also discovered and disabled several improvised explosive devices.

From his house, McGuiness heard the first two shots.

"We were looking at each other while it looked like he was reloading his rifle," McGuiness told Newshub's National Correspondent Patrick Gower.