A 22-year-old Nigerian medical student, Fehintola Moses, has told the BBC about his unsuccessful attempts to leave Sumy, in North East Ukraine, where there has been fighting with Russian troops.

Sumy is also near another front line in Khakiv.

Through WhatsApp message and voice notes, the Nigerian student spoke of how he was unable to leave the city after his university told him that the train lines nearby were controlled by Russian forces.

He said he had been told to stay at the campus.

He said there was no public transport in the city as some roads have been damaged.

"We still have a good supply of food, grocery shops are still open - which I fear may not last long. The school is providing foodstuff for people who need it. We have water. We still trying to sleep and wake up."

"What we need is someone who can remove the Russian soldiers from the streets, someone who can repair the bridges, someone who can make sure the railroads are safe. That's what we honestly need right now."

Moses said he is feeling mentally drained and wishes the whole situation would end.

Over half a million civilians have fled Ukraine, according to the UN.