"Any act of violation against independent nations and people, is, in essence, an abusive offence of the fundamental values of Olympism, which aim towards peaceful coexistence and solidarity," said a statement issued from the office of IOA President Isidoros Kouvelos.

"The International Olympic Academy unites its voice with the International Olympic Committee, firmly condemning the Russian invasion, this moment we are all Ukrainians," it continued.

"All the members, officials and staff of the IOA are standing by the Ukrainian people and the athletes and we hope that the Russian troops, whose presence in the Ukrainian land is an infringement of the Principles and Values of Peace, Friendship and Solidarity among societies, will be withdrawn promptly from the independent Ukraine."

The IOA, originally established in 1961 and reopened last year after renovation, acts as an educational forum for students, educators and officials from across the world.

An annual session for "young participants" which is open to students athletes and others under the age of 35 and selected by National Olympic Committees is the centrepiece of its activities.

The IOA also offers other educational courses including a postgraduate masters degree.

Participants and lecturers have included those from Russia, Belarus and Ukraine.

The move to lower the flags comes as the IOC called for all sporting events to be removed from Belarus and Russia as a demonstration of opposition to the invasion.

More than 210 Ukrainian citizens have been killed, according to Ukrainian Parliament Commissioner for Human Rights Liudmyla Denisova, and in excess of 350,000 people have fled the country.

It is customary for the national flags of Olympic nations to be flown alongside the sports field at the IOA during events held on the site.