One person is understood to be seriously injured following a crash in Drury. 

Police were called about 10.35am to the corner of Pitt Rd and Great South Rd, near Drury, following a serious two-vehicle crash. 

"Initial indications are that one person has been seriously injured," police said in a statement. 

The road will be closed with diversions in place while the Serious Crash Unit attends the scene. 

Police are advising motorists to avoid the area if possible. 

Meanwhile State Highway 6 south of Nelson has now reopened following the earlier crash near Wai-Iti. 

Three people were taken through to hospital in a serious condition. 

Police said inquiries into the circumstances of the crash are ongoing.