Mass shootings in New Zealand: How the attack unfolded

At least 50 people have died in mass shootings at two mosques full of people attending Friday prayers in New Zealand.

Here is what we know so far:

:: Two mosques in Christchurch were targeted, with the deadliest shooting unfolding at the al Noor mosque in the city centre. The Linwood mosque was also attacked.

:: New Zealand police commissioner Mike Bush said there were "multiple fatalities" at both locations. He added that a "number of firearms" had been recovered from "both of the scenes". It had been a "very well-planned event", he told reporters.

:: Police say 49 people have been killed. This is revised on Saturday to 50.

:: Casualties range from young children to adults and the injuries vary between minor and critical, the Canterbury District Health Board's chief executive, David Meates said. Twelve operating theatres are being used and some people will need multiple operations. He said 87 had been taken to hospital, around 20 had serious injuries, including some "very complex cases" and 12 others were in intensive care while seven are in a surgical area and one in an orthopaedic trauma unit.

:: A suspect calling himself Brenton Tarrant in social media posts is believed to have written a 74-page manifesto which explains who he is and the reasons for his actions. The gunman live-streamed the attack showing the pictures on social media platforms. Sky News has decided not to show the video.

:: A man in his late 20s has been charged with murder. Mr Bush did not say whether the same person was responsible for the attacks at both mosques.

:: An image has been published purportedly showing the alleged gunman in Turkey. A senior Turkish official has told Sky News the suspect travelled to Turkey "multiple times and spent an extended period of time in the country". "We believe that the suspect may have travelled to third countries in Europe, Asia and Africa," the official said. "We are currently investigating the suspect's movements and contacts within the country."

:: While three men and one woman are in custody, police say there may be other attackers at large.

:: One of the people apprehended "may have had nothing to do with this incident", Mr Bush said.

:: Those being held were not on any intelligence agency watch lists.

:: Police said they were searching a property in Somerville Street, Dunedin, describing it as a "location of interest in relation to the serious firearms incident in Christchurch". Nearby properties were evacuated "as a precaution".

:: Witnesses said the shooting at the al Noor mosque lasted around 20 minutes, with the gunman going from room to room.

:: Mr Bush said there were "possibly" two improvised explosive devices on a vehicle. "We have disabled one, and are in the process of disabling the other with the assistance of the defence force," he said.

:: Prime Minister Jacinda Ardern said: "It is clear that this can now only be described as a terrorist attack," adding that it was "one of New Zealand's darkest days". The national security threat level had been lifted from low to high, she said.

:: One of the arrested suspects is Australian, the country's prime minister Scott Morrison confirmed.

:: Large parts of Christchurch were placed in lockdown following the shootings, including schools. Police have since begun to lift those restrictions.

:: Mosques nationally have been told to shut their doors, with worshippers warned not to visit until further notice.

:: Bangladesh's cricket team was approaching the al Noor mosque for Friday prayers at the time of the shooting.

:: Police are still treating the incident as ongoing, and members of the public are being urged to stay indoors.