Polish PM Says 'Russian Units' Operating in Ukraine

Poland's prime minister said Wednesday there is evidence that regular units of the Russian army are operating in Ukraine, according to information from NATO and Polish intelligence.

"No one can take seriously talk of separatists in Ukraine at this point," Prime Minister Donald Tusk told parliament regarding the crisis in neighboring Ukraine.

Moscow has denied arming the pro-Kremlin separatists who have been fighting Kiev's rule for four months in an increasingly bloody conflict.

But the Kremlin was forced to admit Tuesday that a number of its troops captured by Ukrainian forces had crossed the border "by accident".

"There is information, which in the last few hours has received additional hard confirmation, that regular Russian units are operating in eastern Ukraine," Tusk said.

"This NATO information -- that has also been confirmed by our intelligence service -- is now practically unambiguous."

He spoke after Ukraine reported Wednesday that a huge convoy of tanks and weaponry from Russia was moving through the southeast of the country.

NATO chief Anders Fogh Rasmussen meanwhile on Wednesday once again accused Russia of escalating the crisis including through direct action against Ukrainian forces with "artillery firing across the border and also inside Ukraine".

Poland has been following the Ukraine events closely, concerned about the impact of Moscow's actions there on its security.

Tusk said Wednesday his intention was not to "heighten the sense of threat but rather to heighten the sense of