ILOVAISK, Ukraine - Burned-out tanks, troop carriers and trucks still lie strewn on the roads and fields all around this town. The body of a Ukrainian soldier hangs doubled over an electric wire, flung up like a doll when his tank exploded. The charred corpse of another soldier lies inside the hull of the tank, a third putrifying torso is tangled in machinery on the road.
It is vivid, if horrifying, evidence of what was a devastating offensive mounted by Russian artillery units at the end of August that smashed the government forces, breaking what had been a relentless advance that had seemed on the verge of crushing the pro-Russian uprising in the country's southeast. Days later, Ukraine agreed to a cease-fire cementing the rebels' hold on the region.
In a matter of five days, beginning on Aug. 28, the previously ill-equipped and inept rebels, backed or led by regular Russian troops and artillery, obliterated almost every Ukrainian position in a 20-square-mile area around this town.
Under withering and highly accurate artillery fire, entire Ukrainian units were virtually wiped out, hundreds of men were killed or wounded, and 250 were taken prisoner, according to rebel commanders. Scores of wounded have filled Ukrainian hospitals, and nearly 100 vehicles were destroyed, some in the fields and villages, others on the roads.
Signs of a panicked, haphazard retreat line the roads around the town. The twisted remnants of burned-out troop carriers and other armored vehicles appear every few miles.
South of Ilovaisk, a large military camp at a dairy farm shows evidence of similarly devastating artillery strikes. Assorted vehicles, trucks and armored personnel carriers, including a command vehicle with communications antenna, were destroyed. Craters from artillery fire pockmarked the fields.
It was a stunning turnaround, engineered in Moscow and carried out by regular Russian troops in what amounted to an invasion, NATO and the Ukrainian government have said.
After the attack, the rebel forces, who just days before had been facing defeat and complaining about a lack of support from Moscow, could be seen driving around the countryside in triumph. Rebel fighters, dressed in camouflage fatigues and carrying automatic rifles, operated checkpoints on the roads and once again control this town and its surroundings.
Ukrainian forces had made steady progress through the summer, pushing the rebels out of several areas and threatening their center of power, the regional capital of Donetsk. They attacked Ilovaisk on Aug. 7 and within a week or so had seized the western part of the town and set up a base in a school building, School No. 14, and in the residential streets around it.
As the soldiers occupied the neighborhood, Victoria and Alexei Babyi fled with their two small children, taping the word DETI, which means children, on the windshield of the car and tying a white sheet to the side mirror.
"We spent a week in the basement, and then we left," said Mrs. Babyi, 28, who with her husband had returned to their trashed house to pick up clothes and other possessions. "There were many Ukrainian checkpoints and military equipment. Planes were flying, and they were bombing the Donetsk checkpoints, and Grad rockets were falling."
As the end of August approached, the rebels still held half of the town, but they were almost surrounded and had a single supply route open to the northeast. But under a barrage of artillery, rebel and Ukrainian commanders say, the balance rapidly shifted. The rebel commander in the town, who goes by the nickname Givi - his real name is Mikhail Tolstykh - described three weeks of heavy fighting leading up to the counterattack.
It was a "massive offensive," Commander Tolstykh said. Heavy artillery positioned about 12 miles away opened up on the Ukrainian forces in support, he said.
Credit Mauricio Lima for The New York Times
Ukrainian soldiers described wave after wave of artillery strikes across the region. Border guards in the south said they were hit even earlier, on the night of Aug. 23, and forced to abandon their positions.
"The Russian Army is very good," said a soldier in one of Ukraine's volunteer battalions farther south, who gave only his nickname, Panzer. "They don't take risks. They see us and bomb in a square. They bomb everything in that square, our positions, a village, homes, everything. We can do nothing; we don't have artillery."
The Ukrainian Army does have some tanks and artillery, but the forces around Ilovaisk, a mixture of army units and lightly armed volunteer units, seem to have been poorly defended.
On Aug. 29, surrounded and under increasing pressure, the men of the Donbass battalion, who had set up headquarters in Ilovaisk's School No. 14, tried to break out in a convoy.
Semyon Semyonchenko, the commander of the battalion, who had been wounded earlier, wrote a real-time chronicle of the fighting on his Facebook page from his hospital bed. He complained that his men had not received any reinforcements. Then, as they pulled out, the convoy was ambushed.
"Now they are fighting, we need help immediately," he wrote. "I can only help and pray that the best sons of Ukraine will survive."
In the village of Novo Ekaterinovo, where the corpses of Ukrainian soldiers lay amid the wreckage, residents said a cannon placed on a hilltop above their homes hit Ukrainian vehicles as they retreated along the road over a period of three days.
"I feel sorry for those men, they are also young lads," a village woman said.
"They are our enemies," replied a rebel soldier who gave only his first name, Yarik, and who accompanied journalists to the area.
But there was little doubt about the effectiveness of the Russian intervention. "It really changed the situation. It gives us more power and the belief that everything will be good for us," said Commander Tolstykh in Ilovaisk. "It showed us that we are one, all the people of the Donetsk republic, and that we are united."
Few people in Ilovaisk dared believe that the fighting was over, however. The town is still without electricity, gas and water.
"We cannot talk of security. We have no idea of who is going to come back. We don't know if it is over," Mrs. Babyi said.