BELGRADE – EU foreign affairs ministers on Monday condemned Russia’s air campaign in Syria, saying it may be guilty of war crimes, and it vowed to impose more sanctions on President Bashar al-Assad’s government.

Calling for an immediate ceasefire in rebel-held east Aleppo, the European Union’s 28 foreign ministers sought to show their anger at the Russian-backed campaign, reports.

“Since the beginning of the offensive by the regime and its allies, notably Russia, the intensity and scale of the aerial bombardment of eastern Aleppo is clearly disproportionate,” the EU said in a statement. Some 275,000 people are believed to be trapped in the area.

The bloc berated Moscow for “the deliberate targeting of hospitals, medical personnel, schools and essential infrastructure,” saying that targeting civilians with barrel bombs and chemical weapons “may amount to war crimes”.

The EU said the atrocities in Syria should be referred to the International Criminal Court, although it was unclear how or when.

It called for an immediate end to conflict, so a peace process could start after almost six years of war, seeking a wider role for EU foreign policy chief Federica Mogherini to talk to regional powers including Iran, Turkey and Saudi Arabia.

While the European Union has no military role in the conflict, the statement marked its harshest criticism of Russia’s role in Syria and came after days of negotiations and resistance from Russia’s allies in Europe.

It was Europe’s second attempt to isolate Russia diplomatically this month, after France and Spain led a push for a UN-backed ceasefire in New York, which Russia vetoed.