WASHINGTON - Fighting in eastern Ukraine has sent some residents fleeing to bomb shelters from previous wars. Despite a cease-fire reached in September, clashes between the government and pro-Russian separatists continue as the two sides fight for control of Donetsk airport. Some civilians are getting caught in the crossfire. 

Kievskiy district in Donetsk is caught in the battle for Donetsk airport. Many shops and residences have been destroyed by shelling in recent days. A group of people who lost their homes have taken refuge in a Stalin-era shelter under an abandoned hospital.

"There was an explosion early this morning. We live in a bomb shelter 10 meters deep, built in the times of Stalin, and even there the ceiling was shaking. I thought, 'Oh my God, something was hit!'… I had to go and get food, because humanitarian help doesn't arrive here anymore. I am now on my way back, but as I get closer to the place, I am scared, as if my soul were saying goodbye to my body," said Valentina Tumanova, a bomb shelter resident.

The government reached a nominal cease-fire with pro-Russian separatists last month, but violations occur almost daily. The fighting has created a shortage of basic amenities, such as food and heating oil, at a time when days are getting shorter and the weather colder.  

"There is no light. It has been already a month since we've lived like that. We pour some sunflower oil on the plate and burn it. We are helping each other to walk," said Galina Ivanovna, another woman living in the bomb shelter.

The fighting in eastern Ukraine began after Russia annexed the Ukrainian peninsula of Crimea in March, and has killed more than 3,600 people.

The government is fighting to maintain control over Donetsk airport, its last outpost in the areas controlled by the local armed forces supported by Moscow. In addition to the conflict over eastern Ukraine, Kyiv has had a long-standing dispute with Moscow over Russian gas supplies. Moscow has twice suspended gas supplies to Ukraine, demanding payment of gas bills.

Ukrainian Prime Minister Arseniy Yatsenyuk on Tuesday warned Ukrainians to be prepared for a new gas crisis this winter.

"I think Russian President Vladimir Putin doesn't want to sign any agreement, and his goal is to freeze Ukraine. And we must be ready for the most difficult scenario. At the moment, we have 17 billion cubic meters of gas. If the European Union additionally opens for us reverse flows of gas - and we are already receiving 60 percent of gas by reverse - then it will hugely ease the way we survive winter," said Yatsenyuk.

But Russian gas for the rest of Europe also flows through Ukraine, so the European Union is not immune to the crisis.  EU leaders will discuss the issue at a summit later this week in Brussels.