KIEV, Ukraine -- Defying a government crackdown, tens of thousands of opposition demonstrators took the streets of the Ukrainian capital Sunday, clashing violently with police.
Riot squads used water cannons, tear gas and noise grenades to combat the demonstrators, many of whom protected themselves with helmets or cooking pots on their heads. The protesters used sticks as weapons and threw stones at police.
Dozens of people were reported injured on both sides. At least two police buses were set on fire.
[Updated, 1:37 p.m. PST Jan. 19: By nightfall, the protesters started to use Molotov cocktails and set three more police buses and at least one police truck on fire. The Interior Ministry reported more than 70 police officers injured, about 40 of them hospitalized.
It appeared that opposition leaders had no leverage over the crowd as the violent confrontation intensified with more injuries on both sides. One protester had his hand torn off by an exploding noise grenade fired by the police, a witness said.]
The crowd, the largest at a demonstration so far this year, gathered around noon local time at a protest tent camp in Independence Square. The dramatic boost in the number of protesters was a response to new security measures aimed at curbing protests that were signed into law by President Victor Yanukovich on Friday.
The controversial bills, hastily adopted in parliament by a simple hand vote, prohibit the erection of tents, stages, sound equipment or other objects that can hinder movement on public streets and venues. The new laws also provide for hefty fines and punishment of up to 15 years in prison.
One of the provisions banned the use of construction helmets popular among protesters since Nov. 30, when riot police violently dispersed a rally of Kiev students protesting Yanukovich's refusal to sign a free-trade and association agreement with the European Union.
On Sunday, responding to the ban, an overwhelming majority of protesters wore helmets, and those who didn't have them wore kitchen pots.
After a rally ended in the early afternoon with opposition leaders again demanding that Yanukovich resign and that new elections be held, thousands of protesters marched toward the government complex less than a mile away, housing parliament and the Council of Ministers.
Many protesters wore gas masks or scarves around their faces; some were armed with sticks and homemade shields.
Early along their route on central Kiev's Grushevsky Street, they were met with police buses blocking their way and several thousand riot police armed with clubs and shields. As the first rocks and bricks flew across the line of buses at the heads of the helmeted police, the officers responded with icy blasts from water cannons -- the air temperature was in the teens -- as well as tear gas and noise grenades, which resounded with deafening thuds.
The protesters started throwing flares at police and set two police buses on fire.
Early in the confrontation, opposition leader and former world heavyweight boxing champion Vitaly Klitschko threw himself between the attackers and police and shouted at the protesters: “What you are doing now is very dangerous! It is a provocation you are being drawn in!”
In response, one protester splashed him in the face with a fire extinguisher, and the crowd resumed its attack with fresh vigor.
As the violence continued, Klitschko returned to Independence Square, where thousands remained, and said he was holding Yanukovich responsible for provoking the violence.
"I am addressing Victor Yanukovich: You are fighting against your own people!” Klitschko said in his short speech. “Stop escalating the situation, don't set riot police on people! Remove police and provocateurs from the streets!”
In the meantime, the Interior Ministry reported on its official website that at least 30 police officers were injured, four of them in grave condition, and also said an investigation was started into mass disorders.
One police officer was taken prisoner and severely beaten by the attackers, the report said, adding: “Upon his release the policeman was hospitalized and diagnosed with a ... brain injury, broken ribs and nose.”
Many protesters in Independence Square criticized the actions of the rioters who attacked the police.
“I agree that we should sabotage the authorities' decisions and actions, but without resorting to violence,” said Alexei Peterchuk, a computer programmer wearing a red plastic helmet. “My friends and I decided not to go to Grushevsky [Street] because by our presence we can only aggravate the provocation which is taking place there now.”
As the violence continued into the night, Klitschko took off to seek an urgent personal meeting with Yanukovich, his spokesperson, Oxana Zinovyeva, told The Times.
The continuing clashes in Grushevsky Street were being broadcast live on the Internet.
Special correspondent Butenko reported from Kiev and staff writer Loiko from Moscow.