BERLIN: Tensions deepened between Germany and Russia over the alleged poisoning of opposition figure Alexei Navalny on Sunday, with Germany threatening sanctions and Russia accusing Berlin of delaying the investigation it demanded. Russian opposition leader and anti-corruption campaigner Navalny fell ill on a flight last month and was treated in a Siberian hospital before being evacuated to Berlin.

Germany said last week there was "unequivocal evidence" that President Vladimir Putin's top foe had been poisoned using the Soviet-era nerve agent Novichok. Germany, which holds the rotating presidency of the European Union, will discuss possible sanctions against Russia if the Kremlin does not provide an explanation soon, Foreign Minister Heiko Maas said Sunday.

"We have high expectations of the Russian government to solve this serious crime," Maas told German daily Bild. "If the government has nothing to do with the attack, then it is in its own interest to back this up with facts."

If Russia does not help clarify what happened "in the coming days", Germany will be compelled to "discuss a response with our allies," Maas said. Any sanctions decided should be "targeted", he added.