Ukrainian authorities scoured parliament for a bomb Tuesday after a threat was called in hours before the legislature was set to vote on whether to approve Prime Minister Arseniy Yatsenyuk's resignation.
No bomb was found and "the anonymous call came from the territory of the Russian Federation," Ukrainian police said in a statement, state news agency Ukrinform reported.
Relations between neighbouring Russia and Ukraine have plummeted to an all-time low since Kiev ousted its pro-Russian president in 2014, and Moscow responded by annexing a part of southern Ukraine and supporting a pro-Russian separatist rebellion that continues to simmer in Ukraine's east.
Yatsenyuk announced that he was resigning on Sunday, amid widespread allegations of corruption in his government. Numerous lawmakers have called for the parliament's speaker, Volodymyr Groysman, to become Yatsenyuk's successor.
But Groysman, a reputed close ally of President Petro Poroshenko, has expressed that he would not want to assume the post, Ukrinform reported Monday.
Poroshenko, who amassed a fortune with his chocolate business Roshen before becoming president amid the protest movement in 2014, has fallen out of favour with many Ukrainians who believe he has failed to weed out corruption among the country's governing elite.
The European Union urged Kiev to "very rapidly" form a new government.
A spokeswoman for EU foreign policy chief Federica Mogherini, Maja Kocijancic, pointed to the need to press ahead with political and economic reforms, as well as the implementation of a peace deal for eastern Ukraine.
Kocijancic praised the "very important work" that Yatsenyuk and his government had undertaken, particularly regarding the country's reform agenda.
Kiev was plunged in political uncertainty in February when the pro-Western coalition lost its legislative majority in parliament, prompting fears of further instability as Ukraine continues to grapple with the conflict in its two eastern-most regions.