This was a poisoned offer by Yanukovich to divide our protest movement.Vitaly Klitschko
However, both men said protests would continue until all their demands, including signing a trade deal with the EU and holding early presidential elections, had been met.
Mr Klitschko, who leads the Ukrainian Alliance for Democratic Reform party, said the offer from resident Viktor Yanukovich was “poisoned”.
“This was a poisoned offer by Yanukovich to divide our protest movement,” he told German newspaper Bild am Sonntag.
“We will keep on negotiating and continue to demand early elections.The protest by Ukrainians against the corrupt president must not have been in vain.”
Overnight demonstrators threw firebombs into the Ukrainian House convention centre in central Kiev, where police were stationed. On Sunday morning anti-government protesters set about cleaning up the debris.
Police responded with teargas to the attack from a large crowd of protesters, which took place amid protester fears that police inside were preparing to disperse demonstrators.
Ukraine’s interior ministry also said that a police officer was shot in the head overnight. Three protesters have been killed in the past week’s clashes, two of them from gunshot wounds and a third of unspecified injuries.