ULAANBATAAR — Mongolia's prime minister has resigned after social media photos of his son's lavish lifestyle sparked an anti-corruption investigation and weeks of mass protests.

Luvsannamsrain Oyun-Erdene, who has denied wrongdoing, lost a confidence vote in parliament on Tuesday.

The viral photos purport to show Oyun-Erdene's son and the son's girlfriend flaunting a black Dior shoulder bag and several shopping bags while on their engagement holiday.

Protesters questioned how Oyun-Erdene's family could afford such luxurious living. Local media reported that the country's anti-corruption body had been looking into their finances.

The photo of the Dior bag, reportedly posted by the girlfriend, had the caption: "Happy birthday to me". Another photo purportedly showed the couple kissing in a swimming pool.

The images have been shared on social media and published by local media.

During Tuesday's confidence vote, 44 of the 88 lawmakers who took part in the secret ballot voted for Oyun-Erdene, while 38 others voted against him. He needed the support of at least 64 of parliament's 126 members.

"It was an honor to serve my country and people in times of difficulties, including pandemics, wars, and tariffs," he said after the vote.

Hundreds of protesters, many of them young people, had been taking to the streets for two weeks before the vote, demanding Oyun-Erdene's resignation.

Oyun-Erdene has rejected allegations of corruption, accusing critics of launching a smear campaign against him.

According to Transparency International, Mongolia has seen worsening corruption since Oyun-Erdene came into power. Last year, it was ranked 114th out of 180 countries in terms of government transparency.

A former communist state sandwiched between Russia and China, Mongolia has been transitioning to democracy since the fall of the Soviet Union in the early 1990s.

Corruption is a persistent problem. Last year, US prosecutors sought to forfeit former Mongolian PM Sukhbaatar Batbold's two New York apartments that he allegedly bought using stolen mining funds.

Batbold, who served from 2012 to 2015, denied wrongdoing.

In recent years, Mongolia has sought to build closer ties with the West, counting the United States and European countries as part of its "third neighbor" foreign policy. — BBC