YEREVAN (REUTERS, AFP) - Mr Serzh Sarkisian, the newly appointed prime minister of Armenia, said on Monday (April 23) he would resign from his post after mass protests against him.

Mr Sarkisian, a close ally of Russian President Vladimir Putin, had served as Armenia's president for a decade until earlier this month and had faced accusations of clinging to power when Parliament voted for him to take up the post of Prime Minister.

Earlier on Monday, pressure on the 63-year-old to quit increased sharply when unarmed Armenian soldiers joined the anti-government protests in the capital Yerevan, which first began on April 13.

"I got it wrong," Mr Sarkisian said in a statement issued by his office.

"In the current situation there are several solutions, but I won't choose any of them. It's not my style. I am quitting the country's leadership and the post of prime minister of Armenia."

Ms Karen Karapetyan, Armenia's first deputy prime minister, will become acting prime minister, the RIA news agency cited the government press service as saying.

Ms Karapetyan, an ally of Mr Sarksyan's, previously served as prime minister from September 2016 to April 2018.

Under a revised Constitution, the prime minister now holds most power in the impoverished southern Caucasus nation, while the presidency has become largely ceremonial.

Mr Sarkisian's move comes after the leader of the mass anti-government protests was released on Monday amid a major protest in the capital, television images showed, following his detention after failed talks with Mr Sarkisian.

Livestreamed images showed Mr Nikol Pashinyan surrounded by his supporters flying Armenian flags in Yerevan, where he has led mass protests against ex-president Sarkisian, who was elected Prime Minister by lawmakers last week.

Hundreds of opposition supporters took to the streets of Armenia's capital on Monday on the 11th day of demonstrations in the former Soviet country.

Young men in small groups briefly blocked roads in Yerevan and shouted slogans such as "Join us!" and "Victory" and the name of Mr Pashinyan as drivers beeped their horns in support.

Hundreds of students, some medical students in white coats, also marched arm-in-arm through the streets, holding Armenian flags.

A group of uniformed former soldiers and veterans who fought in Nagorny Karabakh - a breakaway region seized by Armenian separatists from neighbouring Azerbaijan in a conflict that broke out at the end of the Soviet era - marched with the protesters to Parliament.

Tens of thousands also rallied in Yerevan over the weekend against the rule of Mr Sarkisian.

NEED FOR 'REAL TALKS'

As a lawmaker, Mr Pashinyan is protected by parliamentary immunity and could not be arrested without the approval of fellow MPs.

Under Armenian law, MPs can only be arrested without this approval when they are caught committing a crime, in which case they can be held for up to a maximum of 72 hours.

The Speaker of Armenia's Parliament, the National Assembly, met Mr Pashinyan and other detained politicians overnight, Parliament's spokesman told AFP, without giving details.

Speaker Ara Babloyan was quoted as saying that he had urged Mr Pashinyan and the others "to take part in real talks".

'ENEMY WATCHING'

Defence Minister Vigen Sarkisian warned that Armenia's foe, Azerbaijan, is gaining from the unrest.

"The enemy is looking at events in our country. Instability inside our country opens a road for them to take action. We need to tell society about this," he said at a press conference.

He said the army could only become involved if a state of emergency is declared, which he hopes will not happen "for years to come".

"I think we have not crossed any red lines yet and dialogue can continue," he said. "Dialogue is better than any tension. I am opposed to Armenians coming out against Armenians."

Mr Pashinyan and two other opposition politicians "were detained as they were committing socially dangerous acts", the prosecutor general's office said in a statement on Sunday (April 22).

Mr Sarkisian on Sunday stormed out of tense televised talks with Mr Pashinyan, the leader of the Civil Contract Party, accusing him of "blackmail".

Mr Pashinyan last week announced the "start of a peaceful velvet revolution" in the landlocked country of 2.9 million people.

Hundreds of people were detained at protest rallies across Yerevan on Sunday.

On Monday, Armenia's Investigative Committee, which probes serious crimes, said 26 had been detained on suspicion of "hooliganism" and use of violence against police.

Mr Sarkisian was elected prime minister by lawmakers last week under a new parliamentary system of government that transfers power from the presidency to the premier, while the president becomes largely a ceremonial role.

Mr Sarkisian, a shrewd former military officer, was first elected as president of the impoverished Moscow-allied country in 2008.

After that poll, 10 people died in clashes between police and supporters of the defeated opposition candidate.

He was re-elected in 2013, with his second and final term ending April 9.