Demonstrators speak to police during a protest against an increase of electricity prices in the Armenian capital Yerevan on June 23, 2015. (AFP Photo)
Nearly 6,000 demonstrators rallied in the Armenian capital on Tuesday after riot police used water cannon to break up an earlier protest against electricity price hikes.
Waving national flags and chanting "Shame!" and "No to robbery!" angry protesters flooded Yerevan's central Freedom Square Tuesday evening before marching towards the presidential palace, an AFP journalist reported.
They also demanded the release of nearly 240 people who were detained at dawn when police dispersed a similar protest.
"We will not surrender," young protester Artak Harutyunyan told AFP.
Calling the rally "illegal", Armenia's interior ministry warned protesters against "artificially rising tensions."
Public anger has mounted over the government's decision to hike power prices by over 16 percent from August 1 in the poor ex-Soviet country of 3.2 million, already badly hit by the economic crisis in Russia.
Some 4,000 protesters marched on the presidential palace on Monday, accusing President Serzh Sarkisian's government of failing to combat poverty.
Several hundred remained on the street overnight, holding a sit-in and blocking traffic.
Hundreds of riot police moved in during the early hours to disperse them, using batons and water cannon in the most serious confrontation between protesters and police in the past few years.
Plainclothes officers also beat up journalists and destroyed or confiscated their equipment.
Most of the detained protesters had been released by Tuesday evening.
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.
'Journalists targeted' The prosecutor-general's office said it had opened a probe into "hooliganism and disturbing public order", with protesters facing up to a year in jail if found guilty.
Armenia's health ministry said 25 people, including 11 police, were treated for injuries including fractures.
The US embassy in Armenia said it was concerned by police violence and called for a "full and transparent investigation.
"We are troubled by reports that journalists and their equipment were specifically targeted during the operation," the embassy said.
The EU's mission in Armenia also expressed concern over reports of excessive force against peaceful protesters and violence against journalists, while Amnesty International called for the government to "protect the right to freedom of expression and assembly".
Some political analysts said the protests could have serious consequences.
"Protesters have no links to any political forces whatsoever. This is a purely social rebellion," independent analyst Stepan Safarian told AFP.
"We're witnessing an unprecedented situation in Armenia where a civil protest movement is taking root amid widespread poverty," he said.
"All this may lead to political change."
Armenia's power distribution company, which is owned by the Russian state-controlled holding Inter RAO, requested the government raise electricity tariffs due to a sharp devaluation of the national currency, the dram.
Armenia, an ally of Moscow's, has been hit hard by the economic crisis in Russia brought on by falling oil prices and Western sanctions over Ukraine.
Exports to Russia - Armenia's foremost trading partner - have fallen, as have remittances from Armenians working there, an important source of income for many families.
In January, the country joined the Russian-led Eurasian Economic Union, further increasing Yerevan's dependence on its former imperial master.
The country is economically isolated as its borders with Turkey and Azerbaijan are blocked due to ongoing international disputes.