Russia sent at least 130 aid trucks rolling into rebel-held eastern Ukraine today without the approval of the government in Kiev, declaring that it had lost patience with Ukraine's stalling tactics.
Although Ukraine called the move a "direct invasion" that aimed to provoke an international incident.
The unilateral move sharply raised the stakes in eastern Ukraine, for any attack on the convoy could draw the Russian military directly into the conflict between the Ukrainian government and the separatist rebels in the east.
Ukraine has long accused Russia of supporting and arming the rebels, a charge that Russia denies.
Ukraine had said its troops had recaptured significant parts of Luhansk and suspicions were running high that Moscow's humanitarian operation may instead be aimed at halting Kiev's military momentum.
Fierce fighting has been reported this week both around Luhansk and the largest rebel-held city, Donetsk, with dozens of casualties.
Prime Minister Arseniy Yatsenyuk declared that Russia's plan in sending half-empty trucks into Ukraine was not to deliver aid but to create a provocation by attacking the convoy itself, thus arranging a "provocation."
Ukrainian security services chief Valentyn Nalyvaichenko called the convoy a "direct invasion."
The white-tarped semis, which Russia says are carrying food, water, generators and sleeping bags, aimed to help citizens in Luhansk. The city has seen weeks of heavy shelling that has cut off power, water and phone lines and left food supplies scarce.
Four troops were killed and 23 wounded in the past 24 hours in eastern Ukraine, the government reported at noon Friday.
The International Committee of the Red Cross, which had planned to escort the Russian aid convoy to assuage fears that it was a cover for a Russian invasion, said it had not received enough security guarantees to do so today as shelling had continued overnight in the area.
AP journalists following the convoy across country roads heard the trucks' contents rattling and sliding today, confirming that many vehicles were only partially loaded.
Nalyvaichenko, speaking to reporters in the Ukrainian capital of Kiev, said the men driving the trucks into Ukraine were Russian military personnel "trained to drive combat vehicles, tanks and artillery."
The half-empty aid trucks would be used to transport weapons to rebels and spirit away the bodies of Russian fighters killed in eastern Ukraine, he said.
He insisted, however, that Ukraine would not shell the convoy. Ukraine's presidential administration said Kiev authorised the entrance of only 35 trucks. But the number of Russian vehicles entering the country through a rebel-held border point was clearly way beyond that amount.
Russian customs service representative Rayan Farukshin said all vehicles in the convoy, which counts more than 260 trucks, had been checked and approved for onward travel.
Monitors from the Organization for Security and Cooperation in Europe said as of midday, 134 Russian aid trucks, 12 support vehicles and one ambulance had crossed into Ukraine.
"The Russian side has decided to act," the Russian Foreign Ministry said in a statement. "It is no longer possible to tolerate this lawlessness, outright lies and inability to reach agreements ... We are warning against any attempts to thwart this purely humanitarian mission."
The Russian Foreign Ministry voiced increasing frustration at what it said were Kiev's efforts to stall its delivery.
It had accused the government in Kiev of shelling areas the convoy would have to pass through, making its travel impossible.
The fighting in eastern Ukraine began in mid-April, a month after Russia annexed Ukraine's southern Black Sea peninsula. It has killed over 2,000 people and forced 340,000 to flee, according to the United Nations.
