The EU said Tuesday that an upsurge in fighting between pro-Russian rebels and government forces in eastern Ukraine is an outright breach of the Minsk truce accords and must be stopped immediately.

"The intense fighting around Avdiivka in the last few days, involving heavy shelling with proscribed weapons and leading to a considerable number of casualties, is a blatant violation of the ceasefire, as stipulated by the Minsk agreements," the EU foreign affairs arm said in a statement.