Kamchibek Tashiyev, a leader of a Kyrgyz oppositionist party, was detained on charges to overthrow the government in the wake of a protest rally in Kyrgyz capital, Bishkek, his lawyer said.

A crowd of some 500 people gathered in front of a building housing the parliament and government offices in the center of the capital demanding the nationalization of a vital gold mine owned by a foreign company.

Tashiyev’s lawyer said that his defendant was detained for 48 hours along with three other members of the parliament.

On Wednesday, several rioters were arrested in the wake of the clashes as the crowd left the square and dispersed in small groups in surrounding parks.

The controversial Kumtor gold mine in the east of the country is owned by Toronto-based Centerra Gold.

Although the mine generates over 10 percent of the country’s GDP, it has been the source of a series of toxic spills in past years.