Half a million Indians have set a new world record by performing a mass rendition of their national anthem, as patriotic sentiment rises under a nationalist government.

The "Jana Gana Mana" anthem was sung by 509,261 people in Gujarat, the home state of Hindu nationalist Prime Minister Narendra Modi, at the opening of a Hindu temple, said Guinness World Records.

The feat was accomplished in late January but only validated recently by Guinness World Records.

It smashes the previous record of roughly 254,500 set in the Bangladesh capital Dhaka in 2014.

"We feel very proud to have achieved this record, which is nearly double that of the previous record," Paresh Gajera, chairman of the organising committee overseeing the stunt in the western state, told AFP.