The event is scheduled to run from July 30 to August 1, but the IMMAF said it was forced to change host cities due to the "threat of the escalating COVID-19 situation" in Turkey and "increasing Government restrictions."

A rise in coronavirus cases led the Turkish Government to impose a two-and-a-half-week nationwide lockdown in late April.

The country has registered more than 43,300 deaths from the virus with 282 of those coming in the past 24 hours along with 13,604 new infections.

Bulgaria has staged national level, youth mixed martial arts (MMA) competitions since 2014 and co-hosted the European Championships in 2017.

The IMMAF claimed the Bulgarian MMA Federation (BULMMAF) was "strongly placed" to guarantee the security of the Youth World Championships having received the backing of the country’s Sports Ministry.

"We are grateful to President Nedkov and the Bulgarian MMA Federation for stepping in as the hosts of our 2021 Youth MMA World Championships and thus guaranteeing the event," said IMMAF President Kerrith Brown.

"IMMAF is making every effort to ensure a stable, return to competition for the IMMAF family and looks forward to welcoming our under-18s national teams from around the world to Sofia in the summer."

BULMMAF President Stanislav Nedkov said it was a "great pleasure and honour" to be given the opportunity to stage the Youth World Championships. 

"The award demonstrates a good evaluation of our hosting of the IMMAF European Championships in 2017, to which we gave enormous efforts," added Nedkov.

"We have more than seven years’ experience in organising MMA events and I believe that we can provide a comfortable competition environment for participating nations and, together with the IMMAF team, organise a Youth World Championships that competitors, coaches and all officials can be proud of."

IMMAF said it planned to issue the delayed event handbook to National Federations shortly to enable teams to start registering.