A huge fire has engulfed the National Museum of Brazil in Rio de Janeiro. This is the oldest scientific institution in the country. Firefighters are tackling the blaze at the building, which contains more than 20 million items in its collection. <br />''  <br />'' There have been no reports of any injuries in yesterday's fire so far. The museum, which once served as the residence for the Portuguese royal family, celebrated its 200-year anniversary earlier this year.<br />'' <br />