The sounds of explosions echo through Donetsk at dusk.

According to local authorities, at least 10 civilians were killed when renewed fighting broke out overnight, following a rebel claim that they were receiving fresh supplies of military equipment, and trained fighters, from Russia.

The military says Pro-Russian separatists shot down a Ukrainian warplane over the Luhansk region.

Adding to the tensions, 280 Russian trucks carrying humanitarian aid are waiting near the border of Ukraine.

Sixteen of them are on the move, under the watchful eye of the Red Cross. They say border guards and custom officials have agreed to proceed with inspecting the first group.

Russia claims the convoy is a purely humanitarian mission, but Ukraine says it could serve as a "trojan horse" -- a pretext for an armed invasion.