Ukrainian opposition leader Yulia Tymoshenko has urged President Viktor Yanukovych's opponents not to abandon their protests in central Kiev even though parliament has voted to oust him.

Ms Tymoshenko made an emotional speech to thousands of protesters in Kiev's Independence Square after she was carried on to a stage in a wheelchair.

She said: "You have no right to leave the Maidan (square) ... Don't stop yet."

Ms Tymoshenko, a former prime minister, was discharged earlier from hospital.

She had been held under prison guard for much of the time since she was convicted in 2011 on charges of abuse of office.

Supporters said the case was politically motivated.

Her speech was briefly interrupted by a heckler, but she later carried on addressing the crowd.

Some people welcomed her speech, but others whistled.

Earlier, the Ukrainian parliament declared President Yanukovich constitutionally unable to carry out his duties and set an early election for 25 May.

Politicians in the assembly stood, applauded and sang the national anthem.

In a televised interview this afternoon, Mr Yanukovych denied that he planned to resign and claimed all actions taken by the parliament were illegal.

This morning, protesters took control of the presidential administration building in central Kiev.

Ostap Kryvdyk, a protest leader, told reporters protesters had not used force to enter the compound.

Hundreds of people have also entered the grounds of Mr Yanukovich's sprawling residence outside Kiev.

As it happened this week in Ukraine:

18 February
- Violence erupts as 20,000 pro-European protesters march from Kiev's Independence Square to parliament to demand President Yanukovych be stripped of key powers.
- Kiev shuts down the subway and limits traffic as protesters retake the city hall.
- Riot police break through barricades but thousands of protesters armed with stones, fireworks and petrol bombs refuse to leave the square.
- Unrest spreads to western Ukraine, where protesters swarm public buildings in Lviv.
19 February
- Security forces halt a drive to take over the protest camp as people stream in with food, clothing and medication for demonstrators.
- Mr Yanukovych fires the army's chief and security services announce an "anti-terrorist" operation.
- NATO warns the army not to take part in operations against the protesters.
- Russia calls the protests "an attempted coup d'etat".
- The European Union calls an emergency meeting to discuss sanctions against those behind the unrest, which had killed around 28 people, including ten police officers.
- Mr Yanukovych meets opposition leaders and calls for a "truce".
20 February
- Police open fire, killing more than 60 people according to opposition medics.
- The interior ministry accuses "extremists" of holding 67 of its troops hostage.
- The mayor of Kiev and more than a dozen deputies from Mr Yanukovych's Regions Party resign in protest against the "blood bath".
- The EU says it will impose sanctions on Ukrainians with "blood on their hands" as foreign ministers from France, Germany and Poland meet Mr Yanukovych.
- The US voices "outrage" that Ukrainian troops shot protesters.
- Mr Yanukovych appears ready to hold early elections, a key opposition demand.
21 February
- Interior ministry accuses protesters of shooting at police, opposition issues denial.
- The army's second-in-command resigns, saying the government tried to get soldiers to put down unrest.
- Standard & Poor's lowers long-term credit rating on Ukraine to CCC.
- Mr Yanukovych offers to hold an early presidential election to end the crisis.
- President and opposition leaders sign a deal that includes early elections and the formation of a new unity government.
- Parliament votes to return Ukraine to 2004 constitution, limiting the president's powers.
- Ukraine's parliament impeaches President Yanukovych and sets an election date of 25 May.
- Mr Yanukovych unexpectedly leaves Kiev to attend a conference of political allies in Kharkiv, the eastern city that represents the bedrock of his pro-Russian support.
- Pro-Yanukovych parliament speaker resigns, deputies elect Oleksandr Turchynov, the right-hand man of jailed opposition Yulia Tymoshenko.
- Deputies vote to name another Tymoshenko ally, Arsen Avakov, as interim interior minister.
- Ukraine's interior ministry says "it is at the service of the people and completely shares its aspirations for rapid changes".
- Parliament votes to immediately release Ms Tymoshenko.
- The foreign minister of Germany, who helped mediate Friday's deal to end the crisis, urges all sides to respect the agreement.