Protesters in Kharkiv demanded a vote on the fate of the northeastern Ukrainian city, chanting "Referendum" and "Russia".
They also rallied to remember those killed in clashes between far-right demonstrators and pro-Russian protesters on March 15.
In Donetsk, the protesters took to the streets to show their support for Russia, calling for a referendum similar to the one held in Crimea last week.
They also demanded the resignation of the industrial city's governor, who has been appointed by what they call the illegitimate pro-West leaders in Kiev.
Furthermore, the pro-Russia demonstrators urged authorities to immediately release their leader, Pavel Gubarev, who has been detained by Ukrainian security forces.
Donetsk is situated close to the Russian border and is considered as a stronghold of ousted Ukrainian president, Viktor Yanukovych. The city council has refused to recognize Ukraine’s new government and called for a referendum on the region’s status.
Crimea declared independence from Ukraine and formally applied to become part of the Russian Federation, following a referendum on March 16, in which 96.8 percent of Crimeans voted for union with Russia, with a turnout of 83.1 percent.
On March 21, Russian President Vladimir Putin signed into law documents that officially made the Black Sea Peninsula part of the Russian territory despite condemnation from the West and the new Ukrainian government.
Ukraine has been gripped by a political crisis since November 2013, after Yanukovych refrained from signing an Association Agreement with the European Union in favor of closer ties with Moscow.
SHI/SHI