A highly offensive text message is circulating urging Australians to unite and fight back at a planned Muslim protest in Melbourne.

The message calls on non-Muslim Australians to join a rally to coincide with a planned protest against an 'offensive' Islamic film at Melbourne's State Library on Sunday.

There are fears of potential trouble with the message urging people to 'come ready for a battle for our rights and our land'.

The message even suggests the proposed clash could be worse than the violent scenes witnessed during the Cronulla riots.

It is believed the message, which is littered with highly offensive content, has been circulating for the past few days.

Deputy Commissioner Tim Cartwright has told Fairfax Radio police are taking the text message very seriously.

"This is criminality, vilification and it just the sort of this we don’t want to see.

"If we can track down who is responsible for this we will be dealing them down well before Sunday."

Victorian Muslim leaders yesterday said they did not sanction or support any protests against the film following violent demonstrations in Sydney at the weekend.

They called for those taking part in the rally to do so peacefully.