Anti-mandate protesters are marching through the streets of a student-heavy suburb in Christchurch, as demonstrations in the city ramp up.

About 50 protesters gathered at the Canterbury University campus at 11am today, before they began walking along the Ilam fields.

Numbers have since grown to about 200.

Student magazine CANTA news editor Alex Carter said the protesters' reasoning is to protect the students.

She said they're chanting "What We Want - Freedom", "We Want it Now", "Mandate Over" and "My Body, My Choice".

Across the city about 26 tents are now set up in Cranmer Square, while another protest is underway at the Bridge of Remembrance.

A group of 40 is currently outside the Christchurch police precinct.

Tent cities are springing up across the South Island in sympathy with the Wellington anti-mandate protesters.

A large group has been occupying Picton's Nelson Square Reserve since last week and initially agreed to vacate by 5pm on Wednesday, a Marlborough District Council spokesperson said.

The group has not left yet.

In Dunedin, a smaller number of tents have been erected in the Octagon. The group has been there since the weekend.

The Otago Daily Times reported business owners were unimpressed by protesters occupying the Octagon, but the protesters say they will remain until vaccine mandates are lifted.