Ukrainian border guards began yesterday to inspect a Russian truck convoy carrying aid earmarked for humanitarian relief in eastern Ukraine that has been stranded at the frontier between the two former Soviet republics for nearly a week.

Kiev believes the convoy of some 260 trucks, carrying water, food and medicines, could prove a Trojan horse for Russia to get weapons to pro-Russian separatists battling Ukrainian forces in the region – a notion that Moscow has dismissed as absurd. However, even yesterday it was not clear when the trucks would finally be authorised to enter Ukrainian territory, which at that border point is under rebel control. The rebels granted Kiev’s border guards permission to access the crossing to check the trucks.

A Reuters witness saw 16 trucks move into territory beyond the Russian checkpoint, later followed by a second mini-convoy of 16 vehicles. The aid is intended to alleviate a humanitarian crisis in Luhansk, one of two big cities in Ukraine’s Russian-speaking east which is being held by the rebels. The other is Donetsk, the region’s main industrial hub.

The forces of the Western-backed Kiev government have been steadily gaining the upper hand over the separatists but fighting continues to rage in Donetsk, Luhansk and other urban centres across the Russian-speaking region. Luhansk has been largely cut off by the conflict and is into its 19th day without water and regular supplies of electricity, which have hit mobile and landline phone connections. Only vital foodstuffs are on sale in the few shops remaining open.

Kiev and its Western allies accuse Moscow of supporting and arming the rebels. Moscow denies such allegations but has warned of a “humanitarian catastrophe” in eastern Ukraine.

Ukraine has insisted that the truck convoy comply with border inspections and other formalities before being allowed to cross into its territory under supervision by the Red Cross, which will be responsible for distributing the aid.