More than 5,000 protesters surged through the center of Mongolia's capital to demand that parliament be dissolved and promised aid be handed out.
The largely peaceful rally was the biggest in Ulan Bator since July 2008 when five people were killed and more than 200 hurt in riots over alleged election fraud.
The protesters, many from rural areas and the slums of Ulan Bator, demanded that the government of the Mongolian People's Revolutionary Party and the Mongolian Democratic Party fulfill promises from the 2008 elections to crack down on graft and better distribute the country's mining wealth.
The two parties promised to share more of the country's natural wealth with the public through outright cash grants or through a fund similar to the Alaska Permanent Fund, which pays dividends to the state's residents from oil revenues.
Governments and opposition parties in the impoverished but resource-rich country tucked between China and Russia have argued for years over how to develop and share the benefits of the natural resources.
"Since both parties lied to the Mongolian people, they have no moral right to sit in the parliament," said Uyanga Gantomor, an activist and one of the protest's organizers. She said if the government failed to respond in 72 hours, the protests would enter the "next stage against the corrupt authorities," though she would not say what actions would be taken.
Mongolian media put the number of protesters at more than 5,000. Police declined to give an estimate.
Uyanga called for the government to correct persisting unfairness, saying that 40 percent of Mongolia's 2.7 million people live in poverty, a lingering problem since the country shook off communism nearly two decades ago.
Poverty is likely to worsen after the coldest winter in three decades killed 4.5 million herd animals, about 10 percent of the country's total. Some dispirited herders have in recent weeks streamed into Ulan Bator looking for work or government aid and further straining the city's already stressed social services.
City officials banned the sale of alcohol on Monday, hoping to avoid the drunkenness that some say contributed to the 2008 election violence.
Protesters, some of whom wore blue Buddhist prayer scarves, also called for the cancellation of a recently passed mine investment agreement.
Last August, Mongolian lawmakers voted to phase out a windfall profits tax in 2011, removing the last obstacle to a deal with Rio Tinto Ltd. and Canada's Ivanhoe Mines Ltd. to develop the Oyu Tolgoi gold and copper mine in the Gobi desert. The tax was enacted in 2006 at a time of surging metals prices, but miners said it made tax rates too uncertain and would discourage investment.