New Zealand authorities on Saturday charged the main suspect in the terrorist attack on two mosques with murder a day after the attack that killed 50 worshipers and wounded dozens more which prompted New Zealand Prime Minister Jacinda Ardern to pledge to reform firearms laws in the country.

Brenton Harrison Tarrant, a 28-year-old Australian national, was indicted by a district court in Christchurch, which ordered his detention pending trial before the Supreme Court on April 5.

Tarrant, who was handcuffed and dressed in white prison clothes, did not speak before the court, and his court-appointed lawyer did not ask for his release on bail. Police said he would face more charges.

The Prime Minister’s described the terrorist attack as the worst mass murder in New Zealand, and the authorities raised the level of security risk to the highest level.

The gunman broadcasted live footage on the internet of his attack from a Christchurch mosque. He also published a "statement" on the internet denouncing immigrants and describing them as "invaders".

Police said they detained two other people.

Armed police have been deployed in several locations in all cities of the country, which is unusual as levels of armed violence in New Zealand are low.

Prime Minister Ardern said the main suspect had a license to carry arms and used five weapons in the attack, including two semi-automatic weapons.

"While work is being done as to the chain of events that lead to both the holding of this gun license and the possession of these weapons, I can tell you one thing right now. Our gun laws will change." Ardern said.