Thai authorities have warned traders not to take advantage of shoppers flocking to buy black shirts to mourn King Bhumibol Adulyadej and have sent out teams of inspectors to scour markets for price gougers.

The 88-year-old king died on Thursday after 70 years on the throne, plunging the country into grief.

The government has declared a year of mourning and asked everyone to wear black or white, and to cancel any outdoor festivities, for the first 30 days.