Indian national flags at all government buildings including Red Fort and Rashtrapati Bhavan flew at half-mast on Sunday. This as India observes one-day state mourning as a mark of respect to Britain's Queen Elizabeth II, who died on Sep 8 in Scotland. Meanwhile, the national flag was also flown at half-mast at Victoria Memorial, Calcutta High Court and Raj Bhawan. The state funeral of Queen Elizabeth II will take place on Sep 19 at Westminster Abbey in London. Watch this video to find out how India is paying tribute to the Queen.