Ludhiana is the most populous city in the Indian state of Punjab. The city has an estimated population of 1,618,879 as of the 2011 census and distributed over 310 km2 (120 sq mi), making Ludhiana the most densely populated urban centre in the state. It is a major industrial center of Northern India, referred to as "India's Manchester" by the BBC. It is also known as the commercial capital of Punjab.