The brawl was centred around Homai Station, in Wiri.

A number of people were knocked unconscious during a brawl involving weapons near Homai train station in Wiri, south Auckland on Tuesday.

Police were called to the scene on McVilly Rd about 5.30pm after reports of up to 20 people fighting. High school students were among those involved.

Officers arrived to find a fight involving knives, sticks, and bats, a police communications spokesman said.

A number of people were unconscious but none had life threatening injuries, he said.

A witness said there were people covered with blood and more than 10 police cars at the scene.

Those involved ran to the train station before dispersing on police arrival, the spokesman said.

Several people have been arrested

A worker at a nearby takeaway shop said she called police after a customer alerted her to what was happening nearby.

She said some of the teens were in Manurewa High School uniforms.

Manurewa High School principal Pete Jones said he was aware students from his school had been involved and he'd spoken to police.

"Once we have more details we'll take the appropriate action within the school," he said.

Jones said the fights were not just a school issue but a "community issue".

"We need everyone on board to talk things out, particularly whanau and family."