Kiev. Shelling of the rebel-held eastern Ukrainian city of Donetsk has intensified, as the UN reports the death toll from fighting between government troops and pro-Russia separatists has nearly doubled in the past fortnight.

A spokeswoman for the UN’s human rights office, Cecile Pouilly, said the organisation’s "very conservative estimates” showed the overall death toll had risen to at least 2,086 people as of August 10, up from 1,129 on July 26. Pouilly said at least 4,953 others had been wounded in the fighting since mid-April.

The figures emerged as a spokesman for local authorities in Donetsk told The Associated Press news agency on Wednesday that the shelling had intensified overnight.

The artillery fire had damaged power plants and gas pipelines, leaving large parts of the city without electricity or gas, city council spokesman Maxim Rovinsky said.

The situation in Luhansk, also in rebel hands, was also worsening.

City authorities said on Wednesday they had entered the eleventh straight day without power supplies.

Running water had also dried up and the few shops still open were selling only basic essentials.

With the humanitarian crisis reaching a critical stage, a convoy of nearly 300 lorries, apparently carrying about 2,000 tons of aid, resumed its journey towards Ukraine after lying idle at a Russian depot.

Kiev on Wednesday set conditions for letting the Russian aid shipments in to the rebel-held eastern regions, after earlier vowing to block the massive Russian convoy headed for its borders.

The Ukraine government said it could allow the aid to enter the country after it was inspected by Ukrainian border guards and foreign monitors.

The delay in access came amid fears the convoy could be a "Trojan horse” bringing military help to pro-Moscow rebels who launched a rebellion in the country’s east. Moscow has insisted it coordinated the dispatch of the goods - ranging from baby food and canned meat to portable

generators and sleeping bags - with the international Red Cross, but Ukraine said it was worried the mission may be a cover for an invasion.

There has also been speculation over where the trucks will cross the border - vast portions of which are controlled by the rebels.

Al Jazeera’s Rory Challands, reporting from Crimea, said the convoy seemed to have diverted from its originally intended route.

"The murkiness surrounding this convoy carries on,” our correspondent said.