A four-car crash is set to cause 'significant' delays in Whangarei.

The crash reportedly involved two cars and two trucks and was reported to police at approximately 8.20am.

It happened on the corner of SH1 and Jordan Valley Roads. 

SH1 is completely blocked at the moment and detours are in place either side of Hikurangi.

Two people are reported to be in a serious condition.

Police advise motorists to expect significant delays and avoid the area if possible.

No further information is available at this time.