UPDATED 8.41PM Two people have died after a car hit a tree in Pukekohe this evening.

Police, ambulance and fire are at the scene of the smash on Morgan Rd, which took place at around 7pm.

At least two people were in the car at the time of the crash, and both have since died, police confirmed tonight.

One of the deceased was a man. No further details were available.

Earlier, police said the Fire Service was attempting to ascertain whether there were any other people in the rear of the car.

The road is currently blocked, and motorists have been advised to avoid the area.

Pukekohe East Rd is closed between Runciman Rd and Harrisville Rd.

The serious crash unit is at the scene, and police said the road will be closed for some time.

The Fire Service has referred all calls to police.

Meanwhile, the Southern Motorway is backed up following an earlier crash which blocked the left lane northbound beside the Ellerslie onramp.

Traffic remains heavy northbound between Princes St and Greenlane, the New Zealand Transport Agency (NZTA) said.

Commuters also hit congestion during this evening's rush hour following a crash on the Harbour Bridge. The incident blocked the left lane northbound on the clip-on lane, NZTA said.