Ukrainian authorities on Tuesday reasserted control over an administration building in Kharkiv, the country's second-largest city, evicting pro-Russian protesters and detaining dozens.
In Donetsk, a city 250 kilometers (155 miles) further south, the makings of an improvised self-appointed government began taking shape as demonstrators dug in for their third day at the 11-story regional administration headquarters.
Serhiy Taruta, the officially appointed Donetsk governor, scoffed at events in the city.
''I call this a theater of the absurd,'' he said. ''It is just artists performing, but the main thing is that there is an ever-dwindling audience.''
Both cities are in Ukraine's east, where hostility is strong toward the government that took power in February after the ouster of Kremlin-friendly President Viktor Yanukovych.
Even though Ukraine's interim authorities have achieved some success in quelling unrest that swept across eastern provinces Sunday, festering discontent threatens to undermine plans to hold a presidential election on May 25.
Addressing parliament, acting President Oleksandr Turchynov said security forces retook control of the Kharkiv administration building early Tuesday. He said that several police were injured in the clashes with the separatists.
Interior Minister Arsen Avakov described the measure on his Facebook page as an ''anti-terrorist operation.''
In a session briefly interrupted by a brawl, Parliament also voted to toughen punishment for undermining Ukraine's national security, imposing jail terms of up to 5 years for separatism.
In Donetsk, there was little sign Tuesday afternoon that government forces had any immediate plan to clear the regional administration building.
The city has seen weekly rallies typically culminating in a march on local government offices, but Sunday saw an escalation of that strategy when groups of masked men carrying batons burst through police lines to take over the building.
By Tuesday, lines of car tires wrapped in razor wire had been erected as deterrent against a possible attempt by police to storm the premises. The tactic appears to have been copied from the anti-government protests in the capital, Kiev, which led to Yanukovych's overthrow, when demonstrators set alight tires in order to keep riot police from advancing.
Just like it was in Kiev, feeding stations have been created inside the administration building, supplied by volunteers and local residents.
No clear leader or agenda has emerged from the obscure group of pro-Donetsk autonomy activists behind the standoff.
A declaration adopted Monday claimed sovereignty for what autonomy activists have dubbed the Donetsk Republic and called for a referendum