The morning silence is an uneasy prelude to the artillery fire that inevitably follows. Sealed off from the world by war, some inhabitants hesitantly approach visitors for news. There's no time for anything more than a few words, as soldiers bark instructions at exhausted people boarding evacuation buses with overflowing bags in hand.

On the front lines of Ukraine's separatist war, despair is deepening for a shrinking population that has been without power, heating and running water for almost two weeks.

The relentless rebel advance on the railway town of Debaltseve is being slowed only by Ukrainian tanks, cannons and rocket launchers. A portable mortar stands untended in a sodden field opposite the western entrance to Debaltseve. The weapon has a short-distance range, so the foe is likely close.

As peace negotiations founder, Russian-backed separatists are vowing to swell their ranks and extend their reach. Escape is on the minds of those willing to brave the shells falling on the only open highway out of town. Several rickety government-run buses arrive to ferry people out daily, although those cowering in basements often remain oblivious to this method of flight.

"It is difficult to let people know that the evacuation is going on, and we are doing what we can for now," Sergei Radchenko, the town's barrel-bodied chief of police, said as rescue service workers helped people onto buses.

Fear of the unknown is fueling reluctance among residents to join the displaced. People with family or close friends in Russia or other parts of Ukraine hope for an invitation to move in. Those with nobody say they have nowhere to go.

Outside the town council, Ukrainian National Guard officer Ilya Kiva was overseeing the evacuation. He berated a man, clearly unsteady on his feet, who said he could not leave with his teenage son as his wife had stayed behind at home — telling him to quit drinking and at least let his son board the bus.

"I'll be here tomorrow, and I'll be sober," the man promised forlornly, before slinking away with his son.

Kiva said that emptying the town would free Ukrainian troops' hand to engage in a more aggressive battle: "We come every day and talk to people, we wheedle, we bargain, we plead with them," he said. "We are ready to beg them on our knees to get out of here and let us do our job, which is to destroy the enemy."

Outgoing blasts from howitzers parked near the center of Debaltseve startle the uninitiated. Outside one municipal building — almost all its windows smashed — a group of women waiting in hope of a free bread delivery laughed off the sounds. The heavy artillery duels begin at nightfall, they said.

But distrust toward Ukraine's government and the forces fighting for it runs high.

"All you hear is separatist this, separatist that. And that the National Guard is whiter than white," said Lyudmila, who refused to give her surname out of fear of reprisal from the authorities. "The separatists may have attacked in some places, but our town is mainly being destroyed by the National Guard."

That's an assertion Kiva mockingly dismissed as the provocations of an agitator enlisted by the separatists.

The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron.

Further down the railroad, the separatists recently burst through government lines in Vuhlehirsk, a rural settlement around 10 kilometers (6 miles). Their progress has been systematic and clinical.

Ukrainian military spokesmen paint a different picture in daily briefings: They declare that they have repelled rebel offensives, and repeatedly insist the line will hold.

But along the bottleneck of Ukrainian territory leading out of Debaltseve, evidence abounds of a contingency plan.

Rows of defense trenches have been dug by a bridge 15 kilometers (9 miles) north of the town. Diamond-shaped concrete bollards have been placed across fields to halt possible advances. Tanks parked in the charred remains of a shelled-out house in a village along the highway have their barrels trained on the road, as if in anticipation of an approaching enemy.

Ukraine and many Western nations say the separatists' vast weapons array, matching uniforms and unerring military readiness are all evidence of direct involvement of Russia's armed forces in the conflict.

Moscow denies the accusation. Rebels say their once-ragtag army of a few hundred graduated into a force equipped with tanks, armored trucks, rocket launchers and much else by poaching from Ukraine's notoriously underfunded army.

The leader of the rebels in the main separatist stronghold of Donetsk, Alexander Zakharchenko, stepped up the pressure on Ukraine, declaring this week that plans are afoot to expand the ranks of his forces.

"While we still have time before the spring, new detachments will be able to receive military training," Zakharchenko said. "We expect mobilization to yield at least five additional brigades — five motorized brigades, one artillery brigade and a tank brigade.

The Ukrainian rearguard for the Debaltseve front in Artemivsk, the home of one of the country's best-selling sparkling wines, looks increasingly like a garrison town.

Auto-mechanics and tire shops have seen a sharp pick-up in business repairing damaged vehicles brought in by soldiers. Abandoned Soviet-era plants have been converted into bases. The local stadium is used as a landing pad for helicopters ferrying out the wounded.

Many troops are nervous, jumpy and ill-tempered. On Wednesday, a group of irregulars detained a group of international journalists in the center and threatened to escort them out of the town if they took pictures of military equipment.

The cannonades are fainter in Artemivsk, but they can still be heard. The significance of that is lost on few.

"We have to get rid of these (rebels) in nearby areas, because soon, within a couple steps, they'll be in the town," said Maksim Letovchenko, an 18-year old student at a teaching college in Artemivsk. "If they arrive, there will be nothing left of this place."