What did Russia do after being threatened with more sanctions by the United States, the European Union, and the leaders of the G7 on Friday? It repeatedly violated Ukraine's airspace with fighter jets, of course.

According to the Pentagon, Russian military aircraft entered Ukrainian airspace several times overnight. And for the umpteenth time, Russia was called upon to "de-escalate the situation."

The sanctions, expected to be unrolled next week, are a part of a bid to goad Moscow to stop interfering with Ukraine's efforts to stabilize the eastern part of its country, where battles with pro-Russian separatists are taking place in a number of cities and towns. Just yesterday, Ukrainian Prime Minister Arseniy Yatsenyuk accused Russia of wanting to start World War III. And, as the crisis intensifies, the United States and Russia are reportedly no longer on speaking terms.

In addition to the threat of sanctions, the Ukrainian prime minister's recent whereabouts yesterday might have played a role in compelling Russia to breach Ukraine's airspace:

Elsewhere in the fray, a team of military observers from the Organization for Security and Co-operation in Europe have been detained by pro-Russian forces in eastern Ukraine. According to the separatists currently holding control of the Ukrainian town of Slovyansk, the observers were thought to be NATO spies. The self-proclaimed mayor of the rump city added:

"As we found maps on them containing information about the location of our checkpoints, we get the impression that they are officers carrying out a certain spying mission."

 It's also thought that the hostages may be held for a prisoner exchange.