Four people seriously injured in two unrelated Sunday morning crashes

Police said inquiries into the crashes are ongoing. Photo / NZME

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.