Cox's Bazar, Bangladesh - Digital entrepreneur Mehedi Chowdhury dreamt about owning the new Nissan Sylphy and navigating the congested streets of Dhaka, the Bangladeshi capital, within the car's spacious interior. But then a conflict broke out in neighbouring Myanmar.

"I had just saved enough money to buy the car when I saw those terrible pictures of people crossing the border with no money, no food, no shelter - so I decided to give all my savings to them; I would give twice that if I could," he says.

Nearly 400,000 people from Myanmar's Rohingya minority have sought refuge in Bangladesh over the past three weeks - forced from their homes by a brutal military crackdown which the UN has described as "ethnic cleansing".

Overwhelmed by the influx, Bangladesh has proven to be an inhospitable home. With existing refugee camps at full capacity, thousands have been forced to sleep on the side of the road, huddled under tarpaulins that offer scant relief from the seasonal rains.

Moved by their suffering, citizens of Bangladesh have rallied together to deliver much-needed assistance to the new arrivals. Most distribute their goods from large trucks that now clog the rural road between Cox's Bazar and Teknaf.

A cacophony of car horns and the choking smell of diesel alert the refugees to their presence, who then flock to the road and jostle for prime position.

Their charity comes at a tough time for Bangladesh, which is suffering its worst floods in a century. Seven and a half million people have been affected, with a third of the country under water. Moreover, Bangladesh is one of the poorest countries in the world, with a gross domestic product (GDP) of just $220bn and an average annual income of $1,300.

READ MORE: Message to the world from Ahessan, a Rohingya

'I had to come here to help'

Chowdhury, a programmer and managing director of a digital company, purchased 500 tents and 500 food parcels for Rohingya refugees - a donation which cost him 700,000 Bangladeshi taka (around $8,600).

"They are Muslim, and they are being persecuted because they are Muslim, that strikes a chord with me… and there is only so many times you can watch videos of someone being beaten or raped on Facebook - I had to come here and help," says the 29-year-old. "I am a human being after all."

While impressed by the overwhelming generosity displayed by the host nation, official aid agencies have expressed concern that those truly in need are not being catered for by their "dangerous" distribution methods.

"The only way to do this is to walk though every camp, identify those in need, give them a token and invite them to an orderly distribution centre," says Chris Lom, from the International Organization for Migration.

In one camp, a young girl was wrestled to the floor after catching some bread thrown from a passing tuc-tuc. An older boy emerged from the tussle proudly clutching the misshapen roll, while the girl ran away in tears. On another occasion, an elderly woman staggered away from a frenzied crowd, her leg streaming with blood.

"I did not realise people could fight over a bag of food like that. If they don't get proper support soon then there is going to be a stampede," Chowdhury says.

On Tuesday night, around 1,000 starving Rohingya surrounded his delivery truck. Each food parcel thrown to the crowd initiated a tense and sometimes violent struggle. As the delivery ran low, refugees clambered on board the truck, seizing whatever goods they could find.

"I thought we were going to die," Chowdhury says.

READ MORE: Message to the world from Rashida, a Rohingya

Urgent situation

Despite the risks, Rohingya refugees say they have no choice but to compete for these precious donations.

"If it wasn't for the Bangladeshis I don't know how we would survive. There is no space in the camps, and no international organisations have offered us support," says Noor Mohammed from his roadside settlement.

As he speaks, his six-year-old daughter stands with one foot precariously placed on the tarmac - her wanting eyes fixed on the windscreen of passing vehicles while her hand is poised to receive donations.

Fewer than half of the 20 refugees Al Jazeera spoke to said they had received support from an official aid agency.

"Yes, we all could have done better," says Jean-Jacques Simon at the UN children's agency, UNICEF. "But we are facing some huge challenges… it is unprecedented to see this magnitude of people crossing from one country to another."

Nearly three weeks into the crisis, the UN received a shipment of supplies from abroad.

"In a few days time you will see a surge in supplies," Simon says.

But humanitarian agencies operating in Cox's Bazar still urgently need $77m to meet the demands of the growing refugee population.

That support can not come soon enough for Abu Hayed, a farmer from Jammu Khali village near Teknaf.

Over the past few weeks, he has housed eight Rohingya families in an old cow shed. Unlike most newcomers, they have regular access to food, water and a yard for the children to play in.

"I gave them shelter because I am a human being - it is raining outside, they have nowhere to sleep, they are totally helpless. But I am a poor farmer, with a large family. I am trying to transfer them to a camp, but I am not getting any support," he says, passing a glass of water to one of his tenants.

"We can not look after them for much longer."