The European Union’s top diplomat has joined a growing chorus of international criticism blaming the Russian armed forces for alleged atrocities committed against civilians in Ukraine.

EU foreign policy chief Josep Borrell says “the Russian authorities are responsible for these atrocities, committed while they had effective control of the area. They are subject to the international law of occupation.”

Borrell said Monday that the “haunting images of large numbers of civilian deaths and casualties, as well as destruction of civilian infrastructures show the true face of the brutal war of aggression Russia is waging against Ukraine and its people.”

Working with the U.S., U.K. and other international partners, the EU has been ramping up sanctions against Russia since it invaded Ukraine in February. Borrell says the 27-country bloc “will advance, as a matter of urgency, work on further sanctions against Russia.”