Propped against the decrepit brick ledge lining her stairs, Valentina Pasternak was slow and deliberate with her words.

"I'm an old lady, I don't need this," the 76-year-old said, her lips pale blue from the brutal winter cold. "I don't need this in my life."

The resident of the eastern Ukrainian town of Avdiivka was draped in two scarves and several layers of sweaters, but there was no way she'd stay warm Thursday night. Earlier in the day, a shell hit beside her tiny home and smashed all her windows. Her house was still standing, but the temperature inside was the same as outside: -15 C.

As she spoke, an intense barrage of explosions from artillery strikes erupted in the valley behind her backyard. The sun wasn't down yet, but the fighting had already started again in this beleaguered town of 20,000.

Avdiivka, a government stronghold, has been the target of relentless attacks this week from Russian-backed separatists based in the city of Donetsk, just to the south.

After two years of relative calm, the war in eastern Ukraine has reignited and Avdiivka is the front line.

Intense shelling has left many residents without heat, electricity or water.

Residents of Avdiivka wait for the mobile heating unit to open Friday after it was shelled overnight. (Anton Skiba)

Alexander Hug of the Organization for Security and Co-operation in Europe, who has monitored the Ukrainian conflict since it began in early spring 2014 after Russia annexed Ukraine's Crimean peninsula, held an impromptu press conference in Avdiivka on Friday. As he spoke, explosions could be heard and felt from several directions.

"This is the worst fighting we've seen since 2014-2015 in Ukraine," Hug told reporters.

Monitor Alexander Hug describes the violence in and around Avdiivka. (Anton Skiba)

He said there's no indication the violence will stop. Every night this week, the town has been rocked by heavy artillery that was banned in the Minsk II peace agreement, which, despite being much maligned, had managed to calm the conflict for the past two years.

An exasperated Hug said both sides need to pull their weapons back and end the violence immediately.

Rescue worker killed

Until then, the residents of Avdiivka remain in danger.

"A rescue worker, a young man with a young daughter and wife, was killed overnight," Vladislav Gusyin, a leader of Ukrainian rescue workers dispatched to the town, said Friday.

The 25-year-old was sitting in the front seat of his ambulance outside a humanitarian aid centre when a shell landed nearby. The shrapnel tore iPhone-size holes in the left side of the ambulance. The young man likely died instantly.

A member of the State Emergency Service was killed in his ambulance by an artillery strike. (Anton Skiba)

Earlier that night, and just a short walk away, a woman was killed by a blast while being interviewed by British photojournalist Christopher Nunn.

Nunn was strafed by shrapnel but survived. He was taken to a hospital several hours away where he's been operated on twice, according to Tetiana Gruba, an Anti-Terrorist Operation adviser for the Dnipropetrovsk region. Gruba indicated that contrary to early reports, Nunn didn't lose an eye and doctors said he would recover.

Many residents said the shelling had forced them to sleep in their basements, while others decided to leave town.

A group of women carrying plastic bags filled with aid back to their apartments said they can't believe the war has erupted again.

Many people in town have been without heat, electricity or water for days. (Anton Skiba)

"My son has to stay here and work at the plant," said Vera, 56, who declined to give her last name, "but his wife and daughter had to flee. What kind of life is this?"

Her friends, Liliana, 72, and Natasha, 54, said they're sick of receiving humanitarian aid.

"We just want to work again, like normal people. We want this war to finally stop so we can stop living like this."

An optional evacuation was announced earlier this week, but many kids are still in town with their parents. (Anton Skiba)

Nearby, an elderly couple was left to pick up the pieces after a shell blasted a six-foot hole in the wall of their fourth-floor apartment and knocked off the balcony. The only thing left undamaged in the apartment was an old sewing machine, said Anatoliy Nikolaivich, 70.

"If we were here, we would have been dead."

Nikolaivich and his wife, Elena, were sleeping in their daughter's apartment on the first floor when the shell hit. They spent the morning walking around town, then registered their damage report and awaited a visit from police officials who would produce an official confirmation.

"It was hit by this," said an officer after finding a piece of shrapnel in the couple's home. "It's 122 mm." Today was the officer's birthday, and he spent it going home to home assessing damage.

The aftermath of an artillery blast near an apartment in the centre of town. (Anton Skiba)

After the officer and his team left, the Nikolaivichs stood in the ruins of their home, with the cold air flooding in. Anatoliy turned to his wife, "Let's take a picture, as a memory," he said, causing his daughter, in tears, to let out a slight chuckle.

Elena and Anatoliy said they're too old to start over, and don't anticipate the government or any authorities will help them. They believe they'll have to find a new way forward themselves.

Workers in Avdiivka replace windows to try to keep out the cold and prevent pipes from bursting. (Anton Skiba)

Others, like paramedic Julia Paevska, fear this violence is just the beginning. She says the hospital has seen an enormous influx of wounded people.

"It's only my opinion, but I think the escalation will continue."