Hundreds of Auckland biking advocates force Harbour Bridge lane closures

Two northbound lanes on the Auckland Harbour Bridge have reopened after they were closed by hundreds of cycling protesters on Sunday morning.

A 'Liberate the Lanes' rally was being held at Point Erin Park below the bridge, calling for a three-month trial of a cycle lane.

After the protest, dozens of cyclists went past a police barricade and made their way across the bridge.

The northbound lanes opened after about two hours. The Curran St onramp was also closed.

Police said they were "disappointed" by those who breached the cordons and one person who initially breached the cordon was arrested and is being spoken to.

No injuries were reported.

Motorists are urged to avoid the area and use alternative routes.

"Police are facilitating the group to ensure the safety of rally attendees, and the staff monitoring the event," said a police statement.

Cyclists celebrated the protest with selfies at the summit.