He then exited the mosque through the front door - after just under three minutes inside, and headed into the street - firing random shots as cars drove past.
ESPN Cricinfo reporter Mohammed Isam said members of the Bangladesh cricket team, who are due to play a Test match in Christchurch tomorrow escaped from the mosque. Someone of the same name has posted a manifesto on other social media sites giving the reasons for carrying out the killing, claiming to be an Australian-born, working-class white man.
Dozens of people were shot, many of them killed, when a gunman walked into a packed mosque on Deans Ave near Hagley Park and opened fire with an automatic weapon about 1.40pm local time.
The New Zealand Herald reported there was a second shooting at the Linwood Masjid Mosque.
Another witness said they saw at least four people lying on the ground.
Bush added that the risk for residents remained high and said schools were on lockdown until further notice.
The Guardian reports a bomb has been found in a auto on Strickland Street in Christchurch, around 3km from the mosque where the shooting took place. About 300 people were inside the mosque for afternoon prayers.
"I've lived in Christchurch for twenty-five years plus, I haven't seen anything like this".
Three local schools are now on lockdown.
The Bangladesh Cricket team, who were visiting the city They weren't inside the mosque.
Mobile phone saves Australian man in bow and arrow attack
When the unnamed man raised his iPhone to photograph the attacker, he fired an arrow at him that pierced right through the device. That was the case for a 43-year-old man in Australia who came under attack by another man, according to police.
Police in the New Zealand city of Christchurch said that there are "multiple fatalities" after active shooters opened fire in two mosques in the city center.
"There is no place in New Zealand for such extreme acts of unprecedented violence".
He said he saw the gunman flee before emergency services arrived.
Police Commissioner Mike Bush speaks during a press conference at Royal Society Te Aparangi in Wellington, New Zealand.
On entering the mosque, Peneha said: "I saw dead people everywhere".
The publication also reported that the Bangladeshi Cricket Team had just left the mosque in Christchurch before the attack.
"Police urge anyone in central Christchurch to stay off the streets", he said in a statement.
"It's unbelievably nutty. I don't understand how anyone could do this to these people, to anyone".
A woman told the Christchurch Star she lay in her vehicle near the mosque as four to five men came running towards her.
Police have urged anyone in central Christchurch to stay indoors and report any suspicious behaviour immediately to 111.