Updated

Authorities say they received a threat that a terrorist attack was planned on a plane carrying Ukraine Prime Minister Arseniy Yatsenyuk home after he had addressed European Union leaders in Brussels.

Austria's Interior Ministry said Friday that after receiving a security warning from German flight controllers, SWAT teams boarded the Austrian Airlines flight after its scheduled landing in Vienna Thursday night. They found nothing out of the ordinary.

Yatsenyuk then took his scheduled connection to Kiev.

German flight control spokeswoman Kristina Kelek says the initial warning came from Belgian police and was then relayed by her office to Austrian authorities because the plane was already almost out of German airspace when it was received.

She says it was a vague warning that "there was possibly a terrorist attack planned."