TEHRAN, Young Journalists Club (YJC) - The resource-rich, landlocked country once boasted a booming economy that attracted billions of dollars in investment.
But disputes with foreign investors like Rio Tinto, government overspending and slipping commodity prices tipped Mongolia into an economic crisis in 2016 from which it has yet to fully recover.
"Resign! Resign! Resign!" protesters chanted.
Some carried banners with slogans castigating the government for its perceived failure to tackle corruption, pollution, a stagnant economy and a public health crisis.
"They are not fulfilling the promises they made," a main protest organizer and general secretary of the opposition Democratic Party, Tsevegdorj Tuvaan, told Reuters.
"Parliament has been unable to make the government work and be responsible. So we are today demanding that they take responsibility."
Mongolia had promised to spend heavily on infrastructure, social services and housing by attracting billions of dollars of foreign investment, but that has not materialized.
Some demonstrators carried giant papier-mache caricatures of prominent politicians and life-size cut-outs of the prime minister dressed in a pirate's costume.
The government is run by the Mongolian People's Party, while the presidency is held by Battulga Khaltmaa, a member of the opposition Democratic Party.
Source: Reuters