(WARSAW) - Poland on Thursday warned against the eruption of a regional conflict in Crimea, after pro-Russian gunmen seized government buildings in the peninsula's capital of Simferopol.

"I warn those who have done this (seized buildings) and those who have facilitated it, that regional conflicts begin this way," Polish Foreign Minister Radoslaw Sikorski told reporters in Warsaw.

"This is a very dangerous game," added Sikorski, who along with his French and German counterparts, brokered a roadmap to end bloodshed on Friday in Kiev.

Sikorski's warning came as dozens of pro-Russian gunmen in combat fatigues took control of Ukrainian parliament and government buildings on the Crimea peninsula.

As a result, Ukraine told Russian troops from Moscow's Black Sea Fleet in Sevastapol to remain in their bases.

Sikorski had already warned on Wednesday that a break-up of Ukraine into a pro-Russian east and a pro-European west is an "imaginable catastrophe, but a highly undesirable one".

"The position on Ukraine's (territorial) integrity, towards the entire Ukrainian state, is the basic test for the credibility of each state, which is participating in these historic events," Poland's Prime Minister Donald Tusk also told reporters in Warsaw Thursday.

He was backed by Lithuania's Foreign Minister Linas Linkevicius who, on Thursday, termed the events in Crimea a "provocation" as he arrived in Kiev to meet with the new government.

"The seizure of Crimea parliament and government buildings and the raising of Russian flags in principle is a provocation," the minister told AFP in a telephone interview from Kiev.

"The country whose flags were raised (Russia) must also react to it (...) This provocation must not sprawl into a regional conflict," he added.

An ex-Soviet EU and NATO member, Lithuania played a key role in efforts to seal an EU association pact with Ukraine during its stint as EU president last year.

Yanukovych rejected the agreement at the summit in Lithuanian capital Vilnius in November in favour of an aid deal with Russia, sparking the three months of protests which ultimately led to Yanukovych's ouster at the weekend.

Ex-communist Poland has also long been active in drawing ex-Soviet eastern neighbour Ukraine closer to the EU and NATO, and so further out of the orbit of its Soviet-era master Russia.

Most recently, the two countries co-hosted the Euro 2012 football championships.