Police investigate at the scene of a fatal crash on Aldwins Road, between Ferry Road and Harrow Street.

A man has died in a fiery collision between a car and motorcycle in Christchurch.

Police confirmed the 20-year-old died at the scene of the crash on Aldwins Rd, just north of Ferry Rd, on Tuesday night.

Emergency services were alerted to the crash in Phillipstown at about 6.15pm, a police spokeswoman said.

JOSEPH JOHNSON/STUFF A neighbour described hearing the motorcycle hit a fence and burst into flames.

The motorbike caught fire soon after the crash. Fire and Emergency New Zealand was at the scene.

A neighbour, who did not wish to be named, described hearing the motorbike hit a fence before it became "a big fireball that burned for an hour".

Christchurch Transport Operations Centre spokeswoman Janine Porter said Aldwins Rd was closed in both directions from Ferry Rd to Harrow St.

A police spokeswoman said the road will remain closed overnight.

Motorists were asked to avoid the area while the serious crash unit investigated the circumstances of the crash.