A standoff between riot police and demonstrators protesting a hike in electricity prices is blocking the central avenue in the Armenia capital for the third day running.

An estimated 7,000 protesters joined a second attempt to march toward the presidential residence in Yerevan on Tuesday evening, but were blocked by police. Some of the protesters spent the night behind a row of large trash containers they had placed across the road as a barricade.

Yerevan police chief Ashot Karapetyan appealed to the protesters on Wednesday morning to disperse peacefully.

The unrest is the most serious that Armenia has seen in years, raising concerns about political stability in the impoverished former Soviet nation, which has become increasingly dependent on Russia in recent years.