Ukraine on Saturday launched a terror probe into a bid by an apparently drunk man to force an airliner flying to Turkey to land in Sochi where leaders gathered for the opening of the Winter Olympic Games.

"We have launched an investigation into an attempt to commit an act of terror and an attempt to hijack a plane," Ukrainian Security Service (SBU) investigative department chief Maxim Lenko told reporters.

Ukrainian opposition leader and former interior minister Yuriy Lutsenko has said the country's security services are investigating him for an alleged attempt to "overthrow the state".

Lutsenko, a close ally of jailed pro-Western former prime minister Yulia Tymoshenko, is a key figure in the protest movement locked in a two-month confrontation with Ukraine's President Viktor Yanukovych.

Ukrainian President Viktor Yanukovych is unlikely to move the army against protesters despite opposition warnings about an imminent intervention -- mainly because the loyalty of rank and file soldiers could be in doubt, analysts said.

"The core of the army is made up of young people who grew up in an independent Ukraine," said Valentyn Badrak, director of the Research Center for the Army, Demilitarization and Disarmament in Kiev.

Protesters in Kiev have come up with a novel way to torment riot police -- blasting non-stop news from an opposition television channel projected onto a giant white sheet behind their barricade.

The screen has been set up between two poles on the edge of a giant protest camp in central Kiev -- just a few dozen meters (yards) from lines of riot police defending government buildings.

Ukraine's parliament on Wednesday launched a debate on whether to grant amnesty for detained protesters as the country's first post-independence president warned of civil war.

A day after scrapping tough anti-protest laws that had ignited the latest political turmoil, deputies met in an extraordinary session to consider granting amnesty to those arrested in the anti-government unrest.

Ukraine's prime minister and entire government resigned on Tuesday and its parliament scrapped anti-protest laws that had infuriated the opposition, in the biggest concessions yet to protesters in a two-month crisis.

Ukraine also dominated an EU-Russia summit in Brussels at which Russian President Vladimir Putin struck a conciliatory tone, saying he would not revise the terms of a bailout for Kiev even if the opposition came to power.

A 55-year-old man was found hanged inside the frame of a giant Christmas tree in Kiev on Monday at the main protest camp in the city, the interior ministry said.

"There are no signs of other injury on the body," the ministry said in a statement, indicating a probable suicide.

Thousands in Kiev on Sunday mourned a protester shot dead during clashes, as a rebellion against President Viktor Yanukovych's authority spread despite sweeping concessions offered by the embattled leader.

An emotional crowd packed Saint Michael's Cathedral for the Orthodox funeral to pay their last respects to 25-year-old Mikhail Zhiznevsky, as Pope Francis prayed for dialogue in a country swept by civil strife.

Ukrainian President Viktor Yanukovych on Saturday offered the opposition the post of prime minister and to change the constitution, in a proposed compromise deal aiming to end the country's worst post-independence crisis.

Yanukovych offered top opposition leaders Arseniy Yatsenyuk and Vitali Klitschko the posts of prime minister and deputy prime minister in a brand new government, the presidency said.

Arnold Schwarzenegger on Friday sent a video message of support to anti-government protesters in Ukraine, wishing them luck and making a peace sign.

"I want to send a message to the people of the Ukraine to let them know that I wish them all the best of luck in their peaceful struggle for democracy and freedom," said the deeply tanned action star and former California governor.