The prop-driven observation plane droned lazily overhead like a white vulture, and five minutes later Russian warplanes struck ferociously at the edge of town.

Bombs split trees in nearby woods, dug craters into asphalt, broke windows in houses and burrowed deep into fallow fields -- five bombs in all, exploding with thunderous concussions.

The targets were gaunt, young Chechen militiamen dispersed along a line of trenches. They faced Russian troops no more than 500 yards away, hidden in their own foxholes and obscured by deep stands of trees.

When the roar of the attack jets had turned to a whisper, a phrase rang out along the Chechen line that Muslims use for occasions ranging from giving birth to passing the salt to making war: Allahu Akbar, Allahu Akbar, Allahu Akbar.

"God is Great."

In this case, it meant nobody got hurt.

This was today at the front in the latest war between Russia and separatist Chechnya, a rugged territory in the Caucasus region of southern Russia about 1,000 miles from Moscow. Over the past week, Russian infantry and armored columns have advanced across barren steppes into Chechnya, reaching positions north of the Terek River in a drive supported by heavy airstrikes and massed artillery fire.

Chechen militia forces have dug in along the edge of towns just north of the Terek, blocking the way to Grozny, the capital, about 25 miles to the south. Not infrequently, bombs meant for them hit nearby population centers; town residents have fled back toward the river or across it in search of uncertain refuge.

In two months, this conflict has turned from a defensive campaign by Russian forces to drive a band of Chechen-led Islamic guerrillas from Dagestan, a neighboring Russian region, to a full-scale thrust into Chechnya accompanied by strategic bombing of Chechen roads, bridges, oil depots and power plants in and around Grozny and other key towns.

Once the Chechens might have had world opinion on their side as they confronted the Russian offensive: little, impoverished Chechnya, population 1 million, against a former superpower and its 150 million. But the Chechens have lost the sympathy normally accorded an underdog because an atmosphere of lawlessness in the region has spawned the killings of foreign relief workers and an epidemic of kidnappings for ransom. The Kremlin also has accused Chechen guerrillas of organizing terrorist attacks in Moscow and other Russian cities that killed nearly 300 people.

Chechen officials -- who deny any connection with the Islamic guerrillas -- say the Russians want to seize the territory north of the Terek and set up an alternative Chechen state there that will be beholden to Moscow. The plan, they say, is to demonstrate that Chechnya's de facto independence -- won in 1996 after a two-year guerrilla war against the Russian military -- is a failure. "In their so-called North Chechnya, they will supply electricity and gas, pay pensions, put money into it, all to show how good they are," said Arti Batalov, a top aide to Chechen President Aslan Maskhadov. "Then they will point to poor us and say how terrible we are."

In Moscow, Russian officials have indicated over the past few days that their goal may indeed be to partition Chechnya. If so, Russian forces will have to conquer a string of towns north of the Terek, and it was clear from air attacks here today that such an operation could have horrific consequences.

A crossing of the Terek -- a metal boat is pulled across the shallow river by two young men hauling on a cable -- was interrupted by jets screaming overhead. The aircraft were not visible, but the flares they scattered to deflect heat-seeking antiaircraft missiles were.

The bombs they dropped, somewhere to the east, sounded like clapping waves. Smoke and dust rose from unseen targets. Every half-hour for the next three hours, either airstrikes or salvos of 122mm Grad rockets shook the banks of the river. At the boat landing, frightened civilians lined up, hoping to flee south of the Terek. Women piled blankets on the little boat; an old man wrestled a calf to the ground so he could carry it aboard.

Here in Chernokozovo and in nearby Naurskaya, small craters left by the notoriously erratic Grads pockmarked the streets. Some had shredded cabbages in garden plots. One hit a market, setting it afire. Everyone here seemed to think this is only the beginning.

Tauz Bagaraev, the Chechen district military commander, said there was sporadic combat between his forces and the Russians in several towns in the area. Known fatalities since the Russians arrived here last Thursday were light -- three Chechens, seven Russians and about a dozen civilians. Three Russian soldiers were killed Sunday night when they wandered into town in a civilian sedan; Chechens spotted them, ran them off the road in their own vehicle and opened fire. At least two Russian armored vehicles also were were destroyed, local officials said.

"The Russians are just probing; they retreat at the first sign of resistance," said Bagaraev. He said today that his men would make no attacks on the Russian lines. "But if the fighting goes on, we will change all tactics," he said.

Chernokozovo, like places all over Chechnya, is without electricity, gas or running water as a result of Russian bombardment. A lone hospital is run by one surgeon and two nurses. The surgeon, Uvaes Magomadov, said he is prepared to evacuate the hospital for a basement clinic he has set up on the south side of the river. "I knew this war was coming," he said. "Russia doesn't accept our independence. It's hard here, and the bombing makes people panic. But after a while they become angry and will resist."

He had just stitched the wounds of a soldier who had been hit by shrapnel, and he spotted some bloodstains on his blue tunic. "I myself, when I see blood now, just one drop, I get angry. I am a doctor and pledged to save lives, but if the scalpel is knocked out of my hand, I will kill."

Word circulated in the hospital that four dead Russian soldiers lay on a field not far away, and Chechen militiamen were eager to show them off. A pair of armed guides jauntily led the way, walking briskly past trenches at the edge of town. There, armed men wearing headbands were digging bunkers into low hillsides. Their rations were heavy on home-canned tomatoes and carrots. They greeted one another with "God is Great."

The Russians, they said, were just across an open field, behind the trees. At one point, near where the dead Russians were said to be, a militia leader called a halt. A Russian mortar shell had wounded seven Chechens, he said. It was dangerous. Snipers were busy.

The observation plane made its appearance. No one thought anything of it. Then the attack jets began to roar in. The guides, followed by their charges, ducked behind trees. The first bomb hit, exploding in a field maybe 500 yards off.

A nearby road seemed like a target, so the group ran to a drainage ditch. Another bomb hit, 200 yards away, and trees went flying. There was no warning about the brambles in the ditch.

Three more bombs, but no one looked up to see where they exploded. It was all over in 20 minutes.

Crossing the Terek once again, no one looked back.