“He urges all sides to respect the rules governing the status of IDPs and refugees and to allow safe passage to anyone attempting to leave areas of active military operations,”  Ban’s spokesperson, Stéphane Dujarric, told reporters in New York.

“This tragic incident makes the urgency of a ceasefire and a diplomatic solution even more stark,”  Dujarric added.

According to media reports, the Ukrainian military says many people, including women and children, died when rockets and mortars hit vehicles during on Monday’s attack.

The Secretary-General has repeatedly called for a peaceful resolution of the ongoing crisis in eastern Ukraine and emphasized the need for progress in implementing the peace plan announced by President Petro Poroshenko in June that involves proposals for decentralizing power, holding early elections, and creating a buffer zone on the Ukrainian-Russian border.

 Dujarric added that, in continuation of his good offices,  Ban has asked Under-Secretary-General for Political Affairs Jeffrey Feltman to return to the Ukrainian capital, Kiev, this week.

A resident of the Artema suburb of Sloviansk, Ukraine, in the rubble of what used to be her summer kitchen, in July 2014. Photo: UNHCR/Iva Zimova