A small group of teenagers began the traditional Maori war dance beside a makeshift memorial as others laid flowers, three days after the shootings that left 50 dead.
They were soon joined by dozens more in a show of support for the Muslim community targeted in New Zealand's deadliest shooting in modern history.
Brenton Tarrant, a 28-year-old Australian, has been charged with murder over the attack during Friday prayers and appeared at court on Saturday. He was remanded until 5 April.
The impromptu haka was one of several performed across the city over the weekend.
A group of bikers were filmed performing their own roadside dance near the Al Noor Mosque – one of the two targeted.
Another group of children gathered for a vigil in a nearby park. The haka, performed during the Students Uniting In Love event in Christchurch on Monday, was described as "a student-led initiative to spread love and peace".
Its student organiser told New Zealand news site Stuff the large turnout was proof the horrific events of last week "do not define who we are".
In another show of support for the local Muslim community, a man staged a solo haka outside Christchurch's Deans Avenue mosque.