People in the UK should be “raising their voice” and donating to aid humanitarian efforts in Ukraine and to help those who flee the country, a Unicef spokesman has said.

The United Nations High Commissioner for Refugees (UNHCR) updated its estimate on the number of refugees that have left Ukraine, saying the total stands at 368,000, a figure that continues to rise.

James Elder of Unicef has spoken of “harrowing” scenes in Lviv, in western Ukraine, where he is currently based, with thousands of “everyday people” trying to flee.

He told the PA news agency: “Really it’s just a sort of relentlessly sad place because it was husbands and wives farewelling each other as husband stayed behind and dads farewelling sons and daughters for trains that they didn’t know would come.

“At the border to Poland the queue is about 40 miles of vehicles.

“And even at that 40-mile point, people are starting to walk so that’s about a 10-hour walk. It’s freezing conditions.

“They look like they could be going Sunday shopping, they’re wearing what they would wear and carrying what they can but they tried to flee the country.

“So there’s impressive resolve and determination, but an overwhelming sense of these false farewells, sadness and a lot of stress and anxiety, obviously upon children.”

Unicef has said it is working to help people get access to water, responding to incidents of violence and abuse and ensuring those fleeing the country are adequately supported.

Meanwhile, in Balham, south London, 30 to 40 volunteers at a Polish community centre are sorting through donations from locals.

Mr Elder urged the need for “more support” adding that children should be back in their beds at home and attending school.

Asked what those in the UK should do, he went on: “People can raise their voice which is always good, speak on behalf of others, and then it comes down to the nuts and bolts, Unicef is funded by everyday people, by donors.

“At the moment just any donation made goes towards that water, the sanitation, the schooling and psychological support because kids are traumatised, they’re seeing conflict.

“They’re seeing their parents being ripped away from their families, they don’t know what’s going on, there’s a level of psychological stress and trauma that ideally addressed instantly.

“If people do manage to get out of Ukraine and get all the way to the UK there needs to be a level of tolerance that these people have been through hell and they’ve got the resolve and strength of character that we like to see in people.

“In terms of the Government it is always significant when a big country like the UK can influence others, using strong language to influence donations on the ground at a time like this.”

The UNHCR said humanitarian needs are “multiplying and spreading by the hour”.

It said it is sending more resources, staff and stockpiles to countries neighbouring Ukraine in addition to stockpiles prepositioned in various locations in the region.

The agency said it is sending stock of core relief items to Moldova, including blankets, sleeping mats, family tents, winterisation kits, sleeping bags, water jerrycans, baby kits, solar lamps and other items for at least 10,000 people.

A British Red Cross spokesperson said the charity is “gravely concerned” about the intensification of fighting in Ukraine over the past few days.

The spokesperson said: “People are losing their homes and lives; families are being separated.

“Essential services, like water and healthcare, are under threat.

“We are asking the UK public to help by donating to our Ukraine Crisis Appeal where a donation could help someone affected get food, water, first aid, medicines, warm clothes or shelter.

“A donation will mean we can reach even more people in desperate need.”