Hunkering down at the Kyiv Zoo

STORY: As Ukraine endures an escalating bombardment from Russia, many are fleeing to neighboring countries - others are seeking shelter deep underground.

But Kirill Trentin is staying put to help protect those with nowhere to go -- the animals at the Kyiv Zoo.

“I think four days ago, there was a huge fight near the zoo. And there was an attempt to occupy the military unit. Tracer ammunition was flying all over the zoo."

Trentin, the zoo director - along with his colleagues and their families - have been living together in the zoo for the past week, since the Russian invasion began. They call themselves a 'zoo military commune.'

"It’s stressful for animals. And in the morning after we have to look if anybody was hurt. But there were no obvious signs of injuries, and no one died. But birds were hurting themselves while hitting on cages.”

Trentin says the zoo houses 200 species and nearly 4000 animals.

"All day we are working with animals, and at night we are hiding at shelters because there are attacks."

While the residents of this zoo aren't going anywhere - others are getting out.

A Polish zoo official said a truck carrying six lions, six tigers, two caracals and an African wild dog from a sanctuary east of Kyiv reached Poland on Thursday after a two-day drive to escape the Russian invasion.

Pictures provided by Poland's Poznan Zoo showed workers caring for the animals as they waited to cross the border.

Malgorzata Chodyla is a spokeswoman for the zoo:

"The animals were exhausted, very hungry and very thirsty. We are very grateful to the Ukrainian heroes who brought these animals to us."

Chodyla told Reuters that the animals had been taken to the border by a driver and three older men with no experience in handling wild animals, and who had now gone back to Kyiv to defend their city.