"We urge New Zealanders to stay vigilant and report any suspicious behaviour immediately to 111. We are mobilising resources nationally and support is being brought into the District. We are still working to resolve this incident and we continue to urge Christchurch residents to stay inside. We ask all mosques nationally to shut their doors, and advise that people refrain from visiting these premises until further notice," the police wrote in Twitter.
Police added it was aware of "distressing footage" related to the Christchurch situation, which was circulating online and called on the public not to share the link, saying the work to remove the footage was underway.
Meanwhile, local media published what they called the footage of the mosque shooting, showing the supposed gunman livestreaming his attack.
One of the shooters in New Zealand's Christchurch is believed to be an Australian man who wrote a 73-page manifesto about his plans, local media reported as police said about multiple fatalities due to a firearms incident at at least two locations in the city.
New Zealand's Prime Minister Jacinda Ardern held a press conference about the shootings in the country's east coast city of Christchurch, referring to the incident as "one of New Zealand's darkest days."
"It is clear that this is one of New Zealand's darkest days. What has happened here is an extraordinary and unprecedented act of violence," Ardern told reporters.