In a forest on the outskirts of Kyiv, a group of Ukrainian civilians builds shelters from snow and tree branches as part of a crash course in survival techniques. 

For the participants, the two days of learning how to make fires and get by in sub-zero temperatures have taken on a new urgency as fears swirl over a buildup of Russian troops on the border.  

"If we will have an attack from Russia, it is very important to have these skills," says computer programmer Artem Kuzmenko, 29.

Ukraine is used to war. Since 2014 it has been locked in a conflict with Moscow-backed separatists in the east of the country that has cost over 13,000 lives. 

But of late an increasing number of people in cities like Kyiv have begun looking to prepare for the worst as the West sounds the alarm over a possible full-scale invasion by Russian forces.  

"People in the big cities got used to the fact that the conflict was far away from them," says instructor Sergiy Vyshnevsky, 40, kitted out in military camouflage. 

"Now they realize that the war might come to them."

Vyshnevsky fought on the front line as a volunteer before starting the survival courses for civilians. He details the chaos that could follow any attack -- huge crowds fleeing for the borders, casualties, destroyed infrastructure. 

In recent weeks he has seen a surge in interest as the talk of a potential incursion has grown louder. 

Around 4,000 people have signed up for an online webinar he is giving soon.

"Everyone should know how to build a shelter for their family," he says.

Student psychologist Yana Kaminska, 33, attends the course with her boyfriend as she tries to prepare both physically and mentally for what might be ahead.   

She has already packed an emergency bag in case she has to leave in a rush -- and she knows what her priority would be. 

"First of all it is to look after our families," she says 

"We would make sure they had a safe place for them -- and then we could go back to try to defend our home."

Self-defense 

More and more training sessions have started springing up around Kyiv as people try to bolster their knowledge. 

Around 150 women watched on in a university lecture hall over the weekend as an instructor showed how to incapacitate an unarmed attacker by targeting the pressure points on their head and neck. 

Olena Biletska, whose Ukrainian Women's Guard organisation put on the free self-defence and survival lessons, said that almost 1,000 women had applied, but Covid-19 restrictions meant numbers had to be limited. 

"Everyone understands that their life and health and the health and lives their family are their own personal responsibility," said the lawyer. 

"You need to have at least some knowledge and basic skills."

Ukraine's President Volodymyr Zelensky has desperately sought to calm nerves in the face of a growing clamour of worry from the US. 

And in Kyiv life is carrying on as normal with shops open and restaurants full.

But human resources manager Oleksandra Kovalenko, 25, said she still wanted to be primed for any possibility. 

"You think about and plan for the worst case scenario that could happen -- a military operation -- and an attack is a real possibility," she said. 

Wooden Kalashnikovs 

Elsewhere in the city, around 300 people turned up in the grounds of a former factory for basic military training organised by a nationalist party created from former volunteers who fought in the east. 

The course was entitled "Do not panic, prepare yourself!".

"Panic comes when people do not know how to react, how to use a weapon, how to defend themselves, what to do in case of shooting," trainer Maksym Zhorin, a former commander of the controversial Azov battalion, told participants.

They practised how to hold, aim and move with a gun -- many of them using wooden models of Kalashnikov rifles. 

The students -- who included families with children -- crept through a disused building supposedly occupied by "enemies", learning how to enter a room and kneel down to shoot. 

"Your left leg is still in the wrong place!" a trainer shouted at a young man as he tried to pivot.

Medical instruction was also planned during the training, that the organisers said they aim to repeat next week and hold in other regions. 

"It is my country, how can I not worry," Evgeny Petryk, 20, said after getting to grips with his rifle. 

Like everyone here, he has no idea if an attack is actually coming -- but he isn't taking any chances.  

"Probable or not, it is not for me to judge," he said.

"I am not a fortune teller, but you have to be ready."