Police have broken up what they've labelled a 'volatile' gathering in Wellington and ordered 21 vehicles off the road

Officers set up checkpoints in Petone, Porirua and Seaview last night.

They confronted about 80 bystanders in Taita who'd been blocking the road and throwing bottles.

One vehicle lost control on State Highway 2, broke through a metal barrier and crashed onto the railway lines; the two occupants weren't seriously uninjured.

All up, nearly 80 infringement notices were issued.