A prominent Russian politician who attended the secret funerals of soldiers apparently killed in Ukraine was attacked and hospitalised with a head injury, his party said on Saturday. 

A senior military official said Saturday that Russia wants a "humanitarian bridge" to ferry multiple aid shipments into war-torn areas of eastern Ukraine.

Russian authorities, social organisations and businesses "are thinking of organising not one humanitarian convoy, which we have already sent, but a second, third, tenth," Deputy Defense Minister Anatoly Antonov told the state RIA-Novosti news agency in an interview.

President Vladimir Putin called his Ukrainian counterpart Petro Poroshenko a "partner" and said in a televised interview recorded Friday that they have agreed on Russia's next aid delivery.

Putin said that his meeting with Poroshenko for marathon talks this week "was very good, that was my impression. It was quite frank," according to an extract of an interview to air in full on Channel One television on Sunday evening.

Russian strongman Vladimir Putin first used "Novorossiya" -- the loaded Tsarist-era name for what is now southern and eastern Ukraine -- just after annexing Crimea from Ukraine in March, sparking outrage in Kiev.

The Kremlin made a reference to the term again on Friday when it released Putin's address to Ukraine's pro-Russian separatists, pointedly calling them defenders of "Novorossiya" (New Russia).

European Commission head Jose Manuel Barroso condemned Moscow's "significant incursions" into eastern Ukraine during a phone call with Russian President Vladimir Putin on Friday.

A statement from the commission said Barosso had a "very frank exchange" with Putin, in which he expressed his concern over Russia's direct role in fighting in eastern Ukraine.

Russia on Friday officially labelled a regional rights group that monitors abuses in the armed forces a "foreign agent" as Kiev and the West claimed Russian troops are involved in fighting in Ukraine.

The Russian Justice Ministry added a group called Soldiers' Mothers of Saint Petersburg to its register of "foreign agents". The ruling means the group must use the wording in its paperwork and follow stricter rules.

Germany warned Friday that the Ukraine crisis was spiraling "out of control", as European Union foreign ministers grappled with how to respond to what some termed a Russian invasion.

"The situation in Ukraine is entering a new dimension," German Foreign Minister Frank-Walter Steinmeier told reporters on the sidelines of talks with his EU counterparts in Milan.

The bodies of three Russian airmen killed when their U.N. helicopter was shot down by gunmen in South Sudan were flown home Friday, the peacekeeping mission said.

United Nations aid chief in South Sudan Toby Lanzer, speaking to colleagues gathered at the airport around the coffins draped in U.N. flags, described a "deep sense of shared sadness".

The forces of the Russian-led CSTO military alliance are ready if needed for a peacekeeping operation, a senior official said Friday, as pro-Kremlin fighters were beating back Kiev's troops in eastern Ukraine.

NATO warned Russia on Friday over what it described as a "blatant violation" of Ukraine's sovereignty after the West accused Moscow of direct involvement in the escalating conflict.

Fears of a wider confrontation have spiraled after NATO said Russia had sent troops to fight in Ukraine and funneled huge amounts of heavy weaponry to pro-Kremlin rebels in what Kiev branded an invasion.