Lunchtime in the waterfront district of Beşiktaş in Istanbul on Tuesday and Ismail Orhan has been standing silently under a yellow parasol in the blistering heat for more than four hours.

"We'll be here for weeks, for months," said the 25-year-old, as office workers used their lunch break to join a new wave of passive resistance to the authorities.

Instantly dubbed the "standing man" or "standing people" protest, fuelled rapidly by Twitter and other social media, the mute, peaceful, immobile gesture of resistance to a government that has used brute force to dispel three weeks of protest was launched on Monday evening in Istanbul's Taksim Square by a performance artist, Erdem Gündüz. The "stand-in" instantly spread like a virus.

Silent protesters swelled into hundreds across different parts of Istanbul, to Ankara, Izmir and Antalya. About 10 were detained by police in Istanbul after refusing to move, but were quickly released.

In front of Orhan, by a sculpture of an eagle, were two pairs of flipflops, two pairs of trainers and a pair of tiny baby's bootees – in remembrance of the four people killed during the unprecedented street unrest of the past three weeks and for the pregnant woman who lost her baby when riot police teargassed a luxury hotel on Saturday where terrified protesters and wounded were sheltering.

Tahsin, 63, a bank employee who did not want to use his full name, spent his lunch break joining the handful of protesters, who included elderly women.

"I'm supporting everything that's been going on peacefully for the last two weeks. I wouldn't think we could be arrested. That would be really far fetched," he said.

Hundreds more joined them at different locations. Some brought books to settle in for a long haul. Bottles of water were the most common accompaniment in a poignant and dignified display of rebellion against a government increasingly seen as high-handed and out of touch.

"I'm just stopping, standing, not speaking. Just drinking water," said Merve Uslu, 21, a student. "I heard about the standing man and it touched my heart so much. I don't support clashes with police but we're just resisting basically."

Elsewhere in the city early on Tuesday, however, the Turkish police swooped on dozens of hard-left activists, arresting more than 90 people in the first big clampdown since the prime minister, Recep Tayyip Erdoğan, ordered police to fire tear gas and use water cannons in their attack on Saturday evening to clear Gezi Park of thousands of demonstrators, inciting a night of violence across much of central Istanbul.

Erdoğan's confrontational response to the challenge to his 10-year rule has shocked much of Turkey and brought growing criticism internationally.

On Tuesday, the UN's human rights commissioner, Navi Pillay, called for officials and security forces using excessive force to be punished.

"It is important that the authorities recognise that the initial, extremely heavy-handed response to the protests, which resulted in many injuries, is still a major part of the problem," she said.

But the message from Erdoğan was the very opposite as he divided Turkey into friends and foes, and characterised the largely peaceful protests of recent weeks as orchestrated violence.

"Thanks to this process, we know our enemies and allies as they came out and showed their true colours," said the prime minister.

"The police have been represented as using violence. Who used violence? All of the terrorists, the anarchists, the rioters … In the face of a comprehensive and systematic movement of violence, the police displayed an unprecedented democratic stance and successfully passed the test of democracy."

In addition to Tuesday's arrests, at least 90 protesters were detained during the weekend violence. According to Turkish media reports on Tuesday, most have been released but 13 are to be brought before the courts, which human rights monitors say have been increasingly politicised under Erdoğan.

A lawyer who wished to remain anonymous said the number of arbitrary arrests was very worrying. "Many of those arrested over the course of these protests have been denied access to lawyers for hours; they were made to wait for a long time, some are still waiting," she said. "A red line has definitely been crossed with this."

The prime minister also came under strong attack from other parts of the political spectrum. Selahattin Demirtaş, a co-leader of the main Kurdish political party, the BDP, harshly criticised the government's stance.

Directing his remarks at Erdoğan, he said: "At the moment you look like a leader who tries to stay in power with the help of tanks and batons … This is a movement of the people and you are trying to pit the people against the people."

With the police still out in force on Taksim Square and municipal workers rolling out new lawns, planting rose gardens and new magnolia trees in Gezi Park, the cradle of the rebellion, there were calls for the protest to shift to other park areas across the country on Tuesday evening.

Police weariness appears to be growing, as well as sympathy for the mainly young people they have been confronting for weeks. "This is a good way of demonstrating, a very good way," one riot police officer said of the stand-in. "There is absolutely nothing wrong with peaceful protests; that should be everybody's right."

He laughed when asked if he would consider joining: "I have been standing here for two weeks already anyway."

Determined to carry on with his act of civil disobedience, Orhan said he and his fellow protesters just wanted "peace and democracy". If protesting entailed the prospect of arrest, so be it.

"Under normal circumstances it should not be a crime to just stand here peacefully. But in [Erdoğan's] Turkey, everything is possible."