Kimia Alizadeh, Iran's sole female Olympic medalist, has announced her defection from Iran.

Amid increasing unrest in the Islamic Republic following Tehran's admission that it shot down a Ukrainian passenger jet last week, Alizadeh, who is just 21 years old, posted to her Instagram on Saturday that she has officially defected from Iran.

"Should I start with hello, goodbye, or condolences?" Alizadeh wrote in her native Persian, Agence France-Presse reported.

"They took me wherever they wanted. I wore whatever they said. Every sentence they ordered me to say, I repeated. Whenever they saw fit, they exploited me," she went on to write, CNN reported.

"I wasn't important to them. None of us mattered to them, we were tools," she continued. "The virtue of a woman is not to stretch her legs!"

She also accused the Iranian government of "hypocrisy," "lying," and "injustice," according to AFP.

Alizadeh became the first Iranian woman to win an Olympic medal when she secured the bronze medal in female taekwondo during the 2016 Olympic Games in Rio de Janeiro.

Her defection came just one day after the Iranian government admitted responsibility for shooting down Ukrainian International Flight PS752, killing all 176 people on board, including a large contingency of Iranians and Canadians.

It is not yet clear where Alizadeh has defected to. Initial reports indicated that traveled to Europe.