Chileans voted overwhelmingly in a landmark referendum on Sunday to replace their constitution, long seen by many as underpinning the nation's glaring economic and social inequalities.

A police officer takes body temperature of a visitor at the entrance of a building in Santiago, Chile, March 20. Photo: Xinhua

The result set off wild celebrations across the capital and other cities. 

Thousands of people flocked onto the streets of Santiago amid a cacophony of horn-blaring to celebrate a crushing victory for the "Approve" campaign - by 78.28 percent to 21.72 with over 99 percent of the votes counted.

"I never imagined that us Chileans would be capable of uniting for such a change!" said a jubilant Maria Isabel Nunez, 46, as she walked in the crowd hand-in-hand with her 20-year-old daughter. 

Acknowledging the result, President Sebastian Pinera called on the nation to work together for a "new constitution" in a speech broadcast from his Moneda Palace surrounded by his cabinet.

"This plebiscite is not the end, it is the beginning of a path that we must all walk together to agree on a new constitution for Chile," Pinera said.

"Until now, the constitution has divided us. From today we must all work together so that the new constitution is the great framework of unity, stability and the future."

The result comes as a slap in the face for Chile's political class, according to Marcelo Mella, a political scientist at the University of Santiago.

"Such a strong vote in favor of the constitutional convention should be read as a rejection of the political parties, which to a large extent have been administrators of [Augusto] Pinochet's constitution, of the regime we inherited from him," Mella told AFP. 

Within weeks, Pinera had agreed to initiate a process to draft a new constitution.