German defence minister urges Russia to free Ukrainian sailors

German Defence Minister Ursula von der Leyen on Tuesday urged Russia to immediately release Ukrainian sailors captured at the weekend and said both parties needed to show they were trying to de-escalate the situation.

Ukraine on Monday imposed martial law for 30 days in parts of the country most vulnerable to an attack from Russia, with President Petro Poroshenko saying that was necessary to bolster Ukraine's defences after Russia seized three Ukrainian naval ships and took their crew prisoner at the weekend. 

(With inputs from agencies.)