Some 4,000 protesters angered by the planned price hikes marched on the presidential palace yesterday, accusing President Serzh Sarkisian government of failing to combat poverty in the landlocked Caucasus nation.
Several hundred of them remained on the street overnight, holding a sit-in and blocking traffic.
In the early hours today, hundreds of riot police moved in to disperse the demonstrators, using batons and water cannon to break up the rally in the most serious confrontation between protesters and police in the past few years.
The overnight rally was the culmination of several days of protests aimed at forcing Sarkisian to cancel the tariff hikes, with protests also taking place Monday in several other cities.
More From This Section
Public anger has mounted over the government's decision to hike power prices by over 16 percent from August 1 in the ex-Soviet country of 3.2 million, already badly hit by the economic crisis in Russia.
"Some 237 demonstrators were detained," interior ministry spokesman Armen Malkhasian told AFP.
The office of the prosecutor general said it had opened a probe into "hooliganism and disturbing public order."
Armenia's health ministry said 25 people, including 11 police, were treated for injuries including fractures.
The opposition Armenian National Congress party boycotted a parliament session in protest against the police crackdown, with other opposition MPs demanding that an extraordinary session be convened.
The protest has been organised through social media by a non-partisan group called "No to Robbery."
"We are masters of our country, we will not allow electricity price hikes, we will not let our people be robbed," the group said on Facebook.