Artillery shells hit close to the centre of Ukraine's separatist-held city of Donetsk for the first time yesterday, killing at least one person, as a large Russian aid convoy rumbled towards the border.
With Ukrainian government forces tightening the noose on pro-Russian separatists, shelling rocked Donetsk, sending frightened residents rushing for cover, witnesses said.
It was not clear if the artillery was fired by government or rebel forces. Two shells landed 200 metres from the Park Inn Radisson, one of the city's main hotels, shattering windows.
The blasts opened up a yawning hole on the third floor of an apartment block and left a broad crater on the pavement.
Nearby, a body covered by a sheet lay stretched out on the blood-stained ground.
A huge Russian convoy carrying 2,000 tonnes of water, baby food and other humanitarian aid drove through southern Russia towards the frontier, while Kiev repeated it could not enter until Ukrainian authorities had cleared its cargo.
The convoy left the Moscow region on Tuesday, looking to take aid to Luhansk region, in eastern Ukraine, where the main city is held by the separatists. Russia's Foreign Ministry said there were 262 vehicles in the convoy, including about 200 trucks carrying aid.
The pro-Western Kiev government is fearful that the operation could become a covert military intervention by Moscow to prop up the rebels who appear on the verge of defeat. Moscow denies charges of arming the rebels with tanks, missiles and other heavy military equipment.
In Geneva, a spokeswoman for the International Committee of the Red Cross, which would be responsible for distributing the aid in Ukraine, said: "The question of border-crossing procedures and customs clearance (for the convoy) still have to be clarified between the two sides."
A senior Ukrainian presidential aide said that the Russian cargo could be taken into the country only under the auspices of the Red Cross and on completion of all border formalities.
"Ukraine will not allow onto its territory any accompanying escort for the cargo and any repetition of attempts to send in so-called peacekeepers," said the aide, Valery Chaly.