IZVARYNE, Ukraine   - Ukraine accused Moscow of invading after Russia unilaterally sent the first part of its mammoth aid convoy into eastern Ukraine on Friday, warning against any attacks on the trucks.
Moscow described a week-long delay in allowing the vehicles across the border an “outrage” as it ordered the convoy into rebel-held territory, despite Red Cross officials refusing to provide an escort because of security concerns.  “This is a direct invasion,” the head of Ukraine’s security service, Valentyn Nalyvaychenko, was quoted by news agencies as saying.
As about 70 trucks rolled into the restive territory, Ukraine’s foreign ministry warned that separatist fighters were shelling the convoy’s possible route to the rebel bastion of Lugansk some 63 kilometres (40 miles) away and could be planning a “provocation”.
Ukraine and Russia both said the other side was responsible for the convoy’s security, and Russia’s foreign ministry warned “against any attempts to disrupt a totally humanitarian mission”.
Kiev condemned Moscow’s “deliberate and aggressive” move and said border guards were blocked from checking the contents of most of the white lorries.
Russia has been haggling with Ukraine over the convoy amid fears in Kiev and the West that the trucks could be used to bolster a flagging pro-Russian rebellion in the east or provide a pretext for Russia to send in troops.  Russia insists it just wants to get urgently needed assistance to residents in the stricken region who have been without water and electricity for weeks.  Moscow said it was ready to have Red Cross officials accompany the convoy, but the organisation said it had backed out of the operation because of fierce fighting raging in the area where the trucks are heading.
“We are not part of the convoy in any way,” Victoria Zotikova, the Red Cross spokeswoman in Moscow, told AFP. “We have not received sufficient security guarantees from the fighting parties,” she said, adding that a small team of Red Cross officials in Lugansk reported heavy shelling overnight.
Ukraine’s border service said its officials were effectively “blocked” at the Russian checkpoint as the trucks crossed into Ukraine, violating all prior agreements.
Nearly 300 trucks driven by men in identical beige clothes had been waiting for the green light since arriving at the border over a week ago and there appeared to be progress on Thursday when Ukraine said its officials had started checking the convoy.
An AFP photographer at the scene near the border checkpoint between Russia’s town of Donetsk and Ukraine’s village of Izvaryne said over 70 trucks have crossed into Ukraine, where they met an escort of rebels driving in minivans.
After four months of fighting that has cost some 2,200 lives, Ukrainian forces have been steadily gaining ground with the separatists now surrounded in several key strongholds and street battles starting in populated areas.
Analysts say Kiev and Moscow are both under pressure to strengthen their positions ahead of a meeting between Ukrainian President Petro Poroshenko and Russia’s Vladimir Putin next Tuesday in Minsk where EU officials will also be present.
On Thursday, Poroshenko said his delegation was going to Minsk to “talk peace” but that “to have strong positions during peace talks, we must be strong”.
The presidency said Ukraine will “ask for militants to be taken out of Ukraine” at the meeting, which will also come on the heels of his talks with German Chancellor Angela Merkel who is due in Kiev Saturday.
Russia has however urged Kiev to announce a ceasefire in the conflict area for its convoy to move to Lugansk, the city hardest hit in the conflict and suffering after nearly three weeks without water, power or communication.
- ‘Considerable’ rebel losses -
Kiev’s security forces said Friday the military has made further gains, with the press service for its operation in the east reporting “considerable enemy losses”.
But Kiev also said that pro-Russian rebels shot down a Ukrainian air force helicopter on Wednesday near Lugansk, killing the two-member crew.
Meanwhile, in the southwestern outskirts of the largest rebel-held city of Donetsk, a separatist checkpoint was shelled on Friday by Ukrainian forces nearby.
“We hid in a cellar,” said Valentina, who was woken up by the blasts at 4:30 am. “It was really scary. Whoever did it, God will be their judge.”
“If I only knew where to shelter my children and grandchildren,” she added, showing pieces of shrapnel and broken glass littering her house.