CANBERRA: New Zealand Prime Minister Jacinda Ardern joined hundreds of people in Christchurch on Saturday to commemorate the two-year anniversary of the country's worst mass murder.

Armed with high-capacity semi-automatic weapons, Australian Brenton Tarrant killed 51 people and injured dozens more when he opened fire on Muslim worshippers at the two mosques on March 15, 2019, livestreaming the attacks on Facebook before being arrested.

Ardern said the service - which included speeches from survivors and the family and friends of those killed, - could help heal the deep wounds caused by the attack.

"While words cannot perform miracles, they do have the power to heal. That means we must use them wisely," Ardern told those at the service in Christchurch. "To our Muslim community, that means using our voices and words to acknowledge the loss that was yours."

Tarrant was last year sentenced life in prison without parole, the first time New Zealand has confined anyone for the rest of their life.