Russian aid convoy rolls on

News agencies reported on Thursday that artillery shells had struck either in or close to the center of the city, held by separatist pro-Russian rebels. Reuters cited a witness who said people left their offices in Donetsk's main administration building to take refuge in a stairwell after having been warned to evacuate following two large explosions nearby.

It also cited one of its correspondents in the city who reported hearing at least two further blasts.

AFP quoted one of its correspondents who said a prosecutors' office occupied by separatists had been hit, as well as the building that houses the local technical college.

Ukrainian government forces have been trying to dislodge the separatists, who control Donetsk, for weeks. It and Luhansk are the two biggest cities under the pro-Russian rebels' control.

Russian aid convoy on the move

This came amid reports that a Russian humanitarian aid convoy was approaching the Ukrainian border from the north. Details on the convoy's movement remain sketchy, but the Associated Press said the trucks had passed the southern Russian city of Kamensk-Shakhtinsky and were headed towards a border crossing controlled by pro-Russian rebels.

Ukrainian officials have expressed fears that Russia could be using the humanitarian aid convoy as a cover for running weapons to the rebels or to launch an invasion. Moscow has dismissed this, saying it was working with the International Committee of the Red Cross (ICRC).

However, ICRC spokeswoman Anastasia Isyuk said on Thursday that while talks involving the Ukraine and Russia were continuing, it had not committed to getting involved in the aid operation, in part, at least, because a number of its concerns were still to be resolved.

"The plans keep changing, the discussions are going ahead and we will not confirm for sure until we know an agreement has been reached," she said, speaking to the Associated Press from the ICRC's Geneva headquarters. "The practical details still have to be clarified between the two sides."

Putin for peace

Russian Vladimir Putin, meanwhile, has said that Moscow was committing to halting the bloodshed swiftly.

"The country (Ukraine) has sunk into bloody chaos, in a fratricidal conflict," Putin said. "We will do our best to end this conflict as soon as possible so that the bloodletting in Ukraine ends."

He also said Russia should not allow itself to become isolated, despite Western sanctions imposed over Moscow's alleged role in fomenting the violence in Ukraine, which the Kremlin has responded with counter-sanctions of its own.

"We must calmly, with dignity and effectively build up our country, not fence it off from the outside world," Putin said. "We need to consolidate and mobilize but not for war or any kind of confrontation ... for hard work in the name of Russia."

Putin made the statement while on a visit to Crimea, which Russia annexed from Ukraine earlier this year.

pfd/kms (dpa, AP, AFP, Reuters)