Multiple people are dead and one person is in custody after mass shootings in two Christchurch mosques, in what Prime Minister Jacinda Ardern has labelled "one of New Zealand's darkest days".

Key points:

• Police say they are "unsure" if there are multiple shooters involved in the attacks on two mosques
• Jacinda Ardern has decried it as an "unprecedented act of violence"
• People in Christchurch have been urged to stay indoors, and all schools are in lockdown

 

Police have confirmed they are responding to a "serious and evolving situation is … with an active shooter".

"[The events] involve an active shooter, they involve multiple fatalities," New Zealand police commissioner Mike Bush said.

"We have one person in custody and we are unsure if there are other people.

"The multiple fatalities are, as far as we know, at two locations — a mosque at Deans Ave and another mosque at Linwood Ave Christchurch.

"Again we are unsure if there are any other locations outside of that area that are under threat."

All Christchurch schools are in lockdown and a nearby students' climate strike has been evacuated.

People in central Christchurch have been urged to stay indoors and report any suspicious behaviour immediately to authorities.