A man has been hailed a hero for preventing further deaths in the New Zealand terror attack by confronting the gunman.

During the attack at the second of the two mosques in Christchurch, the Linwood Islamic Centre, Abdul Aziz ran out of the building and attempted to distract the gunman.

Mr Aziz said he picked up a gun the killer had abandoned, pointed it and squeezed the trigger but found it was empty.

The 48-year-old said the gunman then ran back to his car, likely to grab another weapon.

Chase

Mr Aziz said he threw the empty gun at the car window smashing it through.

"He gets into his car and I just got the gun and threw it on his window like an arrow and blasted his window,” he said.

"That's why he got scared."

He said the gunman was cursing at him throughout and yelling that he was going to kill them all.

However, he said, the terrorist drove away and Mr Aziz chased the car down the street to a red light – where he made a U-turn and sped away.

Hero

Latef Alabi, the mosque's acting imam, said: "He (Aziz) went after him...and that's how we were saved. Otherwise, if he managed to come into the mosque, then we would all probably be gone."

Survivor Syed Mazharuddin told the New Zealand Herald that he was praying with about 60 to 70 people at the mosque when he heard gunshots.

He said people began screaming and he "tried to take cover" as the attacker came through the entrance.

"Just around the entrance door there were elderly people sitting there praying and he just started shooting at them."

New Zealand attack

Mr Mazharuddin said the gunman was wearing body armour and shooting indiscriminately.

"There was a lady screaming 'help, help' and he shot her point blank in the face," he said.

"At just that moment, there was one young guy who usually takes care of the mosque and helps with parking and other stuff, so (the man) saw an opportunity and he pounced over to him and grabbed his gun."

Mr Mazharuddin said one of his friends had died at the scene and another was bleeding heavily as he tried to contact emergency services.