Russian Foreign Minister Sergei Lavrov has again warned against the use of force to resolve the crisis in eastern Ukraine where pro-Russia separatists have seized government buildings in at least 10 towns.
Lavrov, speaking on a visit to Beijing on April 15, said the use of force would undermine planned four-way talks on Ukraine on April 17 in Geneva. The discussions would involve Ukraine, Russia, the United States, and the European Union.
Lavrov said "one cannot invite someone to a dialogue with one hand and give criminal orders to use the army against one's own people with the other."
He added that Ukrainian Prime Minister Arseniy Yatsenyuk's offer of dialogue with the separatists was "a step in the right direction, albeit very belated."
Meanwhile, separatists withdrew from the police headquarters in the town of Kramatorsk. Igor Dyomin, a spokesman for the Donetsk region police, said the militants "left of their own accord" the building that they had seized on April 12.
Earlier, Ukraine's acting President Oleksandr Turchynov said security forces overnight on April 15 launched an "antiterrorist operation" in eastern Donetsk region.
Turchynov told a session of parliament that the operation would be conducted in stages, and "in a measured and responsible manner."
The separatists on April 14 ignored a government ultimatum to leave buildings they occupy in eastern Ukraine, but there was no visible sign of government action after the ultimatum expired.
WATCH: Vyacheslav Ponomaryov, a separatist leader in Slovyansk, eastern Ukraine, called a news conference at the occupied city council building on April 14 to ask Russian President Vladimir Putin to send help for pro-Russian protesters in the region. (RFE/RL's Ukrainian Service)
Turchynov accused Russia of harboring "brutal plans" to destabilize Ukraine's southern and eastern regions.
He said Russia wants "to set fire not only to the Donetsk region but to the entire south and east -- from Kharkiv to the Odesa region."
Ukraine's government and the West accuse Moscow of organizing the separatist unrest in the east following the annexation of Ukraine's Crimea. Lavrov on April 15 dismissed the allegations as "nonsense."
Russia says Kyiv provoked the crisis by ignoring the interests of the Russian-speaking population in the east.
The White House said U.S. President Barack Obama, in a telephone conversation on April 14, urged Russian President Vladimir Putin to use his influence to make the separatists stand down.
The Kremlin said Putin rejected claims of Russian agents' involvement in protests as "speculations based on unreliable information."
With reporting by Reuters, AFP, Interfax, and UNIAN