A three-vehicle crash has caused major delays for motorists using State Highway 6 near Nelson.

A police spokesperson said the crash at about 3pm on Wednesday partially blocked Main Rd Hope (SH6), between White and Ranzau Rds, in the Tasman district.

Emergency services were called to the incident, and south and northbound motorists were forced to temporarily use a single lane on a stop/go system.

“Motorists are advised to expect long delays and avoid the area where possible,” the police spokesperson said.

“The Serious Crash Unit is investigating. No serious injuries were reported.”