Security forces and protesters in Ukraine's capital, Kiev, are observing a temporary truce after days of violence.

The arrangement apparently resulted from a meeting between President Viktor Yanukovych and opposition leaders on Thursday, following deadly clashes between the protesters and the state's security forces.

At the protest camp on Independence Square, known as the Maidan, crowd jeered and chanted "revolution" and "shame" when Oleh Tyahnybok, a prominent opposition politician, asked the demonstrators for several more days of the truce, saying that Yanukovych had agreed to ensure the release of dozens of detained protesters and stop further detentions.

Other opposition politicians offered mixed reports on the outcome of the meeting, with Vitali Klitschko saying negotiations had brought little result. Both he and Tyanhnybok were booed at the barricades by the demonstrators.

Al Jazeera's Jennifer Glasse, reporting from Kiev, described the atmosphere in the Maidan as "quiet but very tense".

She also reported seeing fires started by protesters.

The protesters had apparently doused the barricades that had been set on fire, but lit them again during the evening.

Vitali Zakharchenko, Ukraine's interior minster, issued a statement guaranteeing that police would not take action against the Maidan protest camp.

Protesters wary

Al Jazeera's Sue Turton, also reporting from Kiev, said there were reports that Yanukovych had agreed to release all political prisoners within the next three days, but protesters remained wary of that promise.

The developments come after hundreds of enraged protesters in several regions in western Ukraine, where Yanukvoych has little support, seized government offices and forced one governor loyal to Yanukovych to resign.

At least two people were killed by gunfire at the site of clashes in Kiev on Wednesday.

Demonstrators had pelted riot police with barrages of stones and set police buses on fire, while the officers responded with rubber bullets, tear-gas and stun grenades.

Analysis: Ukraine opposition wary of official promises

The opposition maintains that as many as five people died in the clashes, but say they have no evidence as the bodies were removed by authorities.

The Interior Ministry said on Thursday that 73 people had been detained, 52 of whom were being investigated for "mass riots" - a new criminal charge that carries a prison sentence of up to eight years.

Opposition leaders had offered a Thursday evening deadline for the government to make concessions or face renewed clashes.

Although one opposition leader, Arseniy Yatsenyuk, said after the talks that "there is a really good chance" to stop the bloodshed, Klitschko was more pessimistic.

"The only thing we were able to achieve was not much," he told the crowd.

He urged protesters to refrain from violence and continue peaceful protests to avoid further bloodshed.

"I am afraid, yes, I am afraid of human losses," Klitschko said.

"We will be widening the territory of the Maidan further until these guys start reckoning with us."

Yanukovych has called a special session of parliament next week to discuss the tensions, telling the parliament speaker: "The situation demands an urgent settlement."

But there is no indication that the move represents a compromise, since Yanukovych's backers hold a majority of seats.

Police in the dock

Meanwhile, anger spread after a video was released online appearing to show police abusing and humiliating a naked protester in what looked like a location close to the site of Wednesday's clashes in Kiev.

In the video, a young man, his body covered in multiple bruises, wearing nothing but socks, is made to stand on the snow in freezing temperatures, while a policeman punches him in the head and others force him to pose for photos.

Ukraine's Interior Ministry issued a statement, apologising "for the impermissible actions of people wearing police uniforms" and launched an investigation into the incident.

The ongoing country-wide protests began after Yanukovych turned away from closer ties with the EU in favour of getting a rescue loan from Russia.

They turned violent this week after he pushed through harsh anti-protest laws, rejecting protesters' demands that he resign and call new elections.

Source: Al Jazeera and agencies