Mobile phone-users near scene of violent clashes in Kiev receive texts in apparent attempt by authorities to quell protests

"Dear subscriber, you are registered as a participant in a mass riot."

This was the message received by mobile phone-users present near the scene of violent clashes in Kiev early on Tuesday morning, in what appeared to be a novel attempt by authorities to quell the protests that have swept through the city and turned violent on Sunday night.

The language echoed the wording of tough new laws on public gatherings, the passing of which served as a spark for the radicalisation of the protest movement over the weekend. The laws went into effect on Tuesday, and provide for jail sentences of up to 15 years for participating in mass riots.

Prosecutor general Viktor Pshonka issued a statement on Monday calling the disturbances in Kiev "crimes against the state". Ukraine's president, Viktor Yanukovych, said he had tried to listen to peaceful demands but would use "all legal methods provided for by the laws of Ukraine to guarantee public safety".

Kiev city authorities say that 122 protesters were wounded in the clashes, which broke out on Sunday night and saw pitched battles between lines of riot police and angry protesters.

But the organisers say 1,400 people needed medical attention, adding that most were too scared to report their injuries for fear of being accused of participating in mass riots. The police say 163 police officers have been injured in the clashes.

Riot police block a street in Kiev. Photograph: Gleb Garanich/Reuters

The text messages sent to participants appeared to have little effect on a crowd that is angry and increasingly prone to violence.

Yuri Maslovsky, a 38-year-old from Kharkiv who travelled to Kiev to take part in the protests, said he had read about the text messages from his Facebook friends.

"I think these texts are stupid and are targeting people who are easily scared. They are not going to scare off the people who are already protesting."

It was not immediately clear how the messages had been distributed. The interior ministry denied involvement, though said it was studying video footage to determine the most "active participants" in the riots and arrest them.

Telephone provider MTS issued a statement saying it had not been responsible for sending out the messages. "Today we started receiving complaints from users in central Kiev who all received SMS messages from the number 111, containing identical text. We have nothing to do with the distribution."

Another provider, Kyivstar, also said it was innocent of involvement. A statement said: "We strictly observe the confidentiality of our users, their telephone numbers and locations … We know that there is equipment, so-called 'pirate base stations', which allow SMS distribution or calls to all mobile telephone numbers of all operators within a particular area. But, as an operator, we are unable to identify the activity of these stations."

Members of the Ukrainian riot police are caught in a fire caused by gasoline bombs hurled by anti-government protesters. Photograph: Anadolu Agency/Getty Images

On Independence Square, a representative of the impromptu medical service set up to help wounded protesters said he believed that their telephone lines were being monitored by authorities, and advised all of those injured to leave hospital if at all possible.

Oleksandr Shevchenko, a 59-year-old physicist from Kharkiv, said from his hospital bed that he did not take part in clashes but was trying to remove a fence that was hindering the passage of protesters, when he was shot in the face with a rubber bullet.

"I saw blood and went to the medical workers, who brought me to hospital," he said, a huge bruise on his right cheek. The doctors fear that the bullet has damaged his facial nerve. He has been questioned by the police twice as a victim of the clashes, but his lawyer advised him to leave the hospital as soon as possible as the police may accuse him of being a participant.

A top aide to Yanukovych ruled out declaring a state of emergency on Tuesday, but with both sides locked in a stalemate, more violence appears likely in the coming days.

The president has said he will meet a trio of opposition leaders including former heavyweight boxer Vitali Klitschko for talks, but no date has been set and the announcement has been dismissed as an attempt to buy time.

Klitschko went to see Yanukovych for crisis talks on Tuesday, but said that when he arrived, he was told by an aide that the president was busy.

Former heavyweight boxer Vitali Klitschko. Photograph: AP

"I turned around and left," said Klitschko.

In Moscow, Russia's foreign minister, Sergei Lavrov, said that the situation in Kiev threatened to "spin out of control", and said European politicians who have travelled to Kiev and voiced their support for protesters were fuelling the clashes.

Lavrov pointed out that the protesters had occupied government buildings for weeks and entrenched themselves in a central square, as well as using molotov cocktails and other weapons against police in recent days.

He said: "When something like this happens within a European country, no one questions the need to curb the disorder and violence with firm measures."