UKRAINIAN army shelling killed at least 10 residents in Donetsk yesterday despite a supposed ceasefire.

Artillery fire killed four people in a school — all adults, though 70 children were present in the building at the time — and slew six more at a bus stop in the city, which is controlled by anti-fascist separatists.

Fierce fighting was also taking place at Donetsk airport, with regime spokesman Andriy Lysenko and rebel official Alexander Zakharchenko both claiming control of the key facility.

Soldiers and paramilitaries fighting for the Ukrainian government were accused of war crimes as Russian Foreign Minister Sergey Lavrov asked the West to look into mass graves exposed in regime-controlled areas outside Donetsk.

Donetsk official Andrei Purgin said the corpses of nine civilians had recently been unearthed near the city.

But new Nato chief Jens Stoltenberg claimed the ceasefire was working and said ties between the US-led military pact and Russia could now improve.