Hundreds of stone-throwing protesters besieged a Canadian gold mine in Kyrgyzstan on Friday, clashing violently with riot police and prompting the president to declare a state of emergency.

Over 50 people were wounded and 80 detained in the clashes, authorities said.

The protest also triggered widespread unrest in the southern city of Jalal-Abad, where hundreds of people stormed the governor's office.

The twin developments threatened further turmoil in this impoverished Central Asian nation of five million, which hosts a U.S. base supporting military operations in nearby Afghanistan.

Protesters want the Kumtor gold mine in the northeastern part of the country to be nationalized and the company to provide more benefits.

Largest foreign-owned gold mine in post-Soviet bloc

Protesters from the northeastern villages near the Kumtor mine gathered in Tamga and blocked the road to the mine as unrest also erupted in the south of the country. (Vladimir Pirogov/Reuters)

The mine, operated by Toronto-based Centerra Gold (TSX:CG), is the largest foreign-owned gold mine in the former Soviet Union. It accounts for about 12 per cent of the nation's economy and has been at the centre of heated debate between those favouring nationalization and officials who believe that would deter much-needed foreign investment.

Centerra said Friday that an orderly shutdown of its milling facility using power from a backup diesel generator was continuing and that mining operations have been suspended other than those to manage ice and waste.

"Until safe and secure access and grid power has been restored to the facility, it will not be possible for the company to determine the extent of the impact on the operations, including gold production and financial results," the company said in a statement.

Shares in the company were down 39 cents or nearly 10 per cent at $3.76 in trading on the Toronto Stock Exchange on Friday.

Electricity cut off

The demonstrations began earlier this week when protesters blocked the road leading to the mine in the northern Tian Shan mountains.

On Thursday night, several hundred demonstrators, some on horseback, besieged a power transformer unit in the village of Tamga and cut off electricity to the mine for several hours. Riot police moved in overnight, detaining about 80 protesters and restoring the power supply.

By Friday, riot police used stun grenades and rubber bullets to disperse some 2,000 protesters who attempted to storm the Kumtor mine office, the Health Ministry said.

It said at least 55 people, including 13 police, were wounded in clashes and a police bus was set on fire.

Kyrgyz President Almazbek Atambayev declared a state of emergency in the area and the Defence Ministry announced it was deploying forces to protect key facilities.

'Have patience,' deputy PM urges

A senior cabinet member visited the area Friday and tried to persuade the protesters to disperse, saying that further disruptions would cripple the mine and cause significant economic losses.

"The government is asking you to have patience and wait until the autumn, when we will look at the issue," Deputy Prime Minister Shamil Atakhanov told protesters.

But shortly after he spoke, protesters went back to the power transformer unit and cut the power again, forcing the mine to suspend operations.

An excavator loads a dump truck at Kumtor open pit gold mine in the Tien Shan mountains, 350 kilometres southeast of the capital Bishkek near the Chinese border, March 14. (Shamil Zhumatov/Reuters)

The protest quickly spread, engulfing the southern city of Jalal-Abad, where several hundred people stormed a local governor's building, drove officials out and appointed one a "people's governor," the Interfax news agency reported.

The man, Medet Usenov, told Interfax the protesters were demanding the release of several opposition lawmakers jailed on charges of attempting to overthrow the government last October when a demonstration in the capital of Bishkek to demand the nationalization of Kumtor spiralled into a violent confrontation with police.

He added that they intend to name local mayors and district administrators throughout Jalal-Abad province.

Government accuses opposition

Kyrgyz media speculated on Friday that the current government's political rivals could be behind the protests. Former Kyrgyz President Roza Otunbayeva told the AKIpress news agency that they are a planned attempt to topple the government.

Politics in Kyrgyzstan are shaped by clan loyalties and sharp divisions between the north and the south. The ex-Soviet nation on China's mountainous western frontier has seen the violent overthrow of two governments since gaining independence in 1991.

In 2010, the government was overthrown and clashes between ethnic Kyrgyz and minority Uzbeks killed at least 470 people, mostly Uzbeks, and displaced about 400,000 people.