We tried to get everyone to run away from the area because we couldn't open the door for everyone.
Another woman the Herald spoke to said she had been called from her friend who had been shot in the leg and was hysterical - she did not know if her friend was alive.
Police Commissioner Mike Bush said that one person is in custody but police are unsure if there are any other suspects.
Police say officers are responding to a "serious and evolving" situation involving an active shooter. "Christchurch schools will be locked down until further notice.Police thanks the public for their cooperation and will provide further updates to keep residents informed". More information will be added as soon as it becomes available.
"This is not who we are".
Witnesses told media that a man dressed in a military-style, camouflage outfit, and carrying an automatic rifle had started randomly shooting people in the Al Noor mosque.
Radio NZ reported that hundreds of people were praying at the mosque when the shooting took place.
A man who ran from the mosque told him the shooting happened there.
A witness at one of the mosques said the gunman was "continuously shooting for ten to 15 minutes".
New Zealand historically has had only a handful of mass shootings events.
A video has been posted on YouTube that appears to show the mass killing at a Deans Ave mosque in Central Christchurch.
"Police urge anyone in central Christchurch to stay off the streets and report any suspicious behaviour", he said in a statement. "We had to jump the wall to escape", he said.
Local media said there were multiple casualties at one mosque and said another had been evacuated, and there were reports that members of the Bangladesh cricket team were also present at one site.
Ardern at her news conference alluded to anti-immigrant sentiment as the possible motive, saying that while many people affected by the shootings may be migrants or refugees "they have chosen to make New Zealand their home, and it is their home".
This is a developing story.