There are “multiple fatalities” after shootings at two mosques in the city of Christchurch, police in New Zealand have confirmed.

Three men and one woman are in custody, police commissioner Mike Bush told a news conference.

Witnesses told local media they ran for their lives, and saw people bleeding on the ground outside the Al Noor mosque.

Authorities advised all mosques to shut down until further notice. All Christchurch schools are on lockdown.

In a statement to the nation, Prime Minister Jacinda Ardern said details were not yet clear, “but I can tell you now – this will be one of New Zealand’s darkest days”.

Mohan Ibrahim , Who was in the area of the Al Noor Mosque ,at the time ,told New Zealand Herald : “At first we thought it was an electric shock but then all these people started running.

“I still have friends inside.

“I have been calling my friends but there are many I haven’t heard from. I am scared for my friends lives.”

It is not yet known how many shooters there were, but the Herald reports that one gunman is believed to be an Australian who has written a manifesto outlining his intentions. In it, he espouses far-right ideology and anti-immigrant ideology.

Unverified footage purportedly taken by the shooter has emerged, suggesting he filmed as he shot victims. Police called on the public not to share the “extremely distressing” material online.

What happened at the mosques?

The sequence of events remains unclear and has mostly come via eyewitness reports to local media.

Witnesses at the Al Noor mosque, located in central Christchurch along Deans Avenue, facing Hagley Park, reported seeing people bleeding on the ground outside the building.

One unnamed survivor told TV New Zealand he saw a gunman shoot a man directly in the chest. He estimated that the shooting lasted for 20 minutes and that up to 60 people may have been injured.

The gunman reportedly targeted the men’s prayer room in the mosque, then moved to the women’s room.

“What I did was basically just waiting and praying, God please, let this guy run out of bullets,” the witness said.

“He came to this side, he shot this side, he went to another room and went to the ladies’ section and shot them. I just heard one of the ladies has died.”

A Palestinian man who did not wish to be named told AFP news agency he saw a man shot in the head, and heard rapid gunfire.

“I heard three quick shots, then after about 10 seconds it started again – it must have been an automatic, no one could pull a trigger that quick.

“Then people started running out. Some were covered in blood.”

A second mosque in the suburb of Linwood has also been evacuated, and the police commissioner said “multiple fatalities” were recorded at two locations. There are far fewer details emerging from there, however.

How are the authorities responding?

A spokeswoman said Canterbury District Health Board (CDHB) has activated its mass casualty plan, according to New Zealand news site Stuff.co.nz.

The plan includes clearing emergency room space for casualties. The spokeswoman did not comment on how many patients were expected.

Police earlier cleared Cathedral Square, where thousands of children were holding a rally for action on climate change.

Police Commissioner Mike Bush said: “Police are responding with its full capability to manage the situation, but the risk environment remains extremely high.

“Police recommend that residents across Christchurch remain off the streets and indoors until further notice.”

Parents have been told not to go to schools to collect their children. New Zealand Police tweeted: “There is no timeframe at this stage for when the lockdown will be lifted. The children are being taken care of by schools.”

Who has been caught up in the attack?

As well as the numerous witness reports of casualties, the Bangladesh national cricket team appear to have narrowly escaped the shooting.

A reporter following the team, who were due to play New Zealand in a now-cancelled test match on Saturday, tweeted that the team had “escaped from a mosque near Hagley Park where there were active shooters”.

Player Tamim Iqbal tweeted that the “entire team got saved from active shooters”.

Bangladesh Cricket Board spokesman Jalal Yunus said most of the team had gone to mosque by bus and were about to go inside when the incident took place.

“They are safe. But they are mentally shocked. We have asked the team to stay confined in the hotel,” he told the AFP news agency.