A row over an unpaid restaurant bill in a western Indian city has escalated into a riot between Hindus and Muslims that's left four people dead and 175 injured.

The unrest broke out in Dhule in Maharashtra state on Sunday, special inspector-general Deven Bharti said.

Deadly row ... Indian police inspect a damaged vehicle at the site of clashes over an unpaid restaurant bill. Credit:AFP

Four rioters were killed by police firing while 113 policemen were among the injured, he said.

Bharti said investigations were still under way, but it appeared a quarrel over a restaurant bill had provoked a mass brawl that left shops smashed, motorbikes burned and glass strewn across the streets.