and they seem to be Russian.

The Washington Post quotes a Ukranian military official:

Russian forces in two armored columns captured a key southeastern coastal town near the Russian border Thursday after Ukrainian forces retreated in the face of superior firepower, a Ukrainian military spokesman said.

    The two Russian columns, including tanks and armored fighting vehicles, entered the town of Novoazovsk on the Sea of Azov after a battle in which Ukrainian army positions came under fire from Grad rockets launched from Russian territory, according to the spokesman, Col. Andriy Lysenko.

    “Our border servicemen and guardsmen retreated as they did not have heavy equipment,” Lysenko said in a statement.

    Ukrainian authorities have denounced the latest fighting as a Russian invasion of their territory, intended to prop up pro-Moscow separatists who have been losing ground to Ukrainian forces and to open a new front in the southeastern corner of Ukraine.

Updating:

I suspect much more news will be forthcoming in the next hours. Here is the New York Times on the President's news conference:

Mr. Obama declined to call the latest reports of Russian military units moving into Ukraine an invasion, as others have, saying they are “not really a shift” but “a little more overt” version of longstanding violations of Ukrainian sovereignty. “I consider the actions that we’ve seen in the last week a continuation of what’s been taking place for months now,” he said. “These separatists are backed, trained, armed, financed by Russia. Throughout this process we’ve seen deep Russian involvement in everything that they’ve done.”

Mr. Obama’s tone was strikingly more restrained than that of his ambassador to the United Nations, Samantha Power, who earlier in the day bluntly accused Russia of lying about its military intervention in Ukraine. In a blistering statement to the Security Council, Ms. Power said “the mask is coming off” Russia’s actions, which she called “a threat to all of our peace and security.”