A fire has destroyed an Hitachi air conditioner plant in India's western Gujarat state, gutting the property worth millions of dollars.

At least 20 fire trucks were called in to battle the blaze at the Japanese firm, with no casualties having been reported.

"Material inside the plant is blowing air to fire. We are removing the metal sheets so that we can douse the fire," said Chief Fire Officer Dasul.

The cause of the fire has not been determined.