"I ran behind the mosque", he told TVNZ.
Ms Jamieson said shaken survivors had told her how the shooting unfolded.
Several casualties were reported by witnesses but emergency services are yet to confirm any details.
The police recommended that residents across Christchurch remain off the streets and said schools would be locked down until further notice.
The New Zealand Police subsequently issued another update saying that they were dealing with a "serious and evolving situation" that was occurring in Christchurch.
Bangladesh's cricket team escaped unscathed after a deadly shooting at a mosque in New Zealand, an official told AFP on Friday. The gunman is believed to still be at large.
Armed police have been deployed after receiving reports of shots fired in the city center at 1:40 p.m. Friday local time.
ESPNcricinfo journalist Mohammad Isam reports Bangladesh's Test cricketers were about to enter the mosque for a prayer session.
"I heard a big sound of the gun".
"I spoke to one of them shortly after [the incident]". Lots of people were sitting on the floor.
"When that was happening, one of the players had called me to contact the police".
A mass casualty plan has been activated in the greater Canterbury region, which includes the city of Christchurch. I don't know how many (gunshots) there were.
Shootings were reported at the Al Noor Mosque, the Linwood Masjid mosque and Christchurch Hospital.
"It was very traumatic there and people were running out from that mosque presumably, and the Bangladesh players were coming out".
Witnesses say as many as 300 people were inside the Christchurch mosque when a man wearing a military-style jacket opened fire.
All members of the Bangladesh Cricket Team in Christchurch, New Zealand are safely back in the hotel following the incident of shooting in the city.
Police at the cordon around a shooting incident in central Christchurch.