Aid trucks clearing customs

Photo: The Canadian Press. All rights reserved.

Ukrainian soldiers gather at a point close to Luhansk, eastern Ukraine, Wednesday, Aug. 20, 2014. (AP Photo/Petro Zadorozhnyy)

Some Russian trucks in a massive aid convoy began the process of clearing customs Thursday at a rebel-held border crossing in eastern Ukraine, the Ukrainian border guard service said.

Russia has been trying to send in over 200 trucks carrying what it says is humanitarian aid to help civilians in the hard-hit city of Luhansk, but Ukraine fears the move is a ploy to aid the pro-Russian separatists who have been fighting government troops. The convoy has been held up at the border for a week in a dispute over the conditions under which Ukraine will let in the Russian trucks.

Ukraine has accused Russia of arming and supporting the separatists since fighting began in mid-April, a charge Russia has denied.

News about the convoy comes as Ukrainian troops have made significant advances into rebel-held territory this week in a conflict that has already claimed more than 2,000 lives and forced over 340,000 people to flee their homes. Ukraine celebrates Independence Day on Sunday and reports are rife that the government is aiming to achieve a breakthrough by that date.

Fierce fighting was still reported Thursday in Luhansk, a day after the government said it had captured much of the rebel stronghold 20 kilometres from the Russian border, Andriy Lysenko, spokesman for the Ukrainian National Security Council, told reporters in Kyiv.

The city has been under siege for 19 days, lacking basic amenities like running water or electricity. Residents there are struggling to survive, the International Committee of the Red Cross said Thursday following a visit to Luhansk a day earlier.

"People hardly leave their homes for fear of being caught in the middle of ongoing fighting, with intermittent shelling into residential areas placing civilians at risk," the ICRC said in a statement.

The agency said it has taken all necessary preparatory steps for the passage of the Russian convoy, which remains at the border. It said it was ready to deliver the aid to Luhansk if both Russia and Ukraine agreed on the strictly humanitarian nature of the convoy and all parties in the fighting gave the Red Cross assurances of safe passage.

Ukrainian troops claimed Thursday to have seized two Russian armoured vehicles outside of Luhansk. Photos provided by the defence ministry showed one vehicle and an array of Russian civilian and army IDs.

Moscow denied the reports. A spokesman for Russia's defence ministry told Russian news agencies that the armoured vehicle in the photos did not belong to Russia and the documents found in the vehicle had not been used for five years.