At least 42 are dead from riots in the port city of Odessa as violence has now spread far beyond the eastern strong holds of pro-Russian militias. At least 37 of those are pro-Russian rioters who died when they took shelter in a trade union building that was set afire.

Ukraine is spinning out of control.

Reuters:

The military operation in the east was overshadowed by the violence in Odessa, a vibrant multi-ethnic port city that has seen some support for separatists but nothing like the riots that erupted on Friday.

Police said four people were killed, at least three shot dead, and dozens wounded in unprecedented running battles between people backing Kiev and pro-Russian activists. The clashes ended with separatists holed up in a the building that caught fire. Television footage showed petrol bombs exploding against its walls.

At least 37 people died in the blaze. On Saturday police raised the overall death toll in the city to 42. It was easily the biggest death toll since about 100 people were killed in Kiev protests that toppled pro-Russian President Viktor Yanukovich in February.

"Kiev and its Western sponsors are practically provoking the bloodshed and bear direct responsibility for it," RIA Novosti quoted Kremlin spokesman Dmitry Peskov as telling reporters.

Peskov also said Friday's violence made the idea of holding presidential elections in Ukraine on May 25 "absurd".

Regional police chief Petro Lutsiuk said on Saturday more than 130 people had been detained and could face charges ranging from participating in riots to premeditated murder

In one bit of good news, OSCE observers captured last month by pro-Russian forces have been freed:

The April 4 capture of the military monitors, on a mission from the Organization for Security and Cooperation in Europe, was a major diplomatic issue for the West and their release could help relieve pressure on Moscow.

The separatists initially described the monitors, led by a German colonel, as prisoners of war. One Swede was freed earlier on health grounds while four Germans, a Czech, a Dane and a Pole were still being held until Saturday. A Russian envoy helped negotiate their release.

The separatist leader in Slaviansk, self-proclaimed "people's mayor" Vyacheslav Ponomaryov, said they were freed along with five Ukrainian captives, with no conditions.

"As I promised them, we celebrated my birthday yesterday and they left. As I said, they were my guests."

At a news conference yesterday, President Obama and German Chancellor Angela Merkel both talked up additional sanctions to be placed on Russia if Putin doesn't change course. But the pinpricks represented by sanctions are not likely to deter Vladimir Putin from doing whatever he wants.

And we're likely to find out what that is sooner rather than later.