From political activists freed after years in Myanmar's jails to stricken and impoverished families, all are welcome at Yangon's Muslim Free Hospital -- a symbol of unity in a country riven by religious unrest.

There is barely a space left unoccupied in the bustling medical centre. From the soot-smeared front steps, through dusty stairwells and into sweltering wards, people wait for treatments that would be beyond their reach elsewhere in Myanmar's desperately underfunded health system.

The throngs of people -- the hospital sees up to 500 outpatients a day -- are a testament to the diversity of the Buddhist-majority country's main city, with flashes of colour from Myanmar skirt-like longyis and Muslim headscarves.

"I am a surgeon so my responsibility is to cure suffering patients," Tin Myo Win said before setting out on a tour of the wards.

"The policy of this hospital is not to discriminate. It does not matter whether people are rich or poor, or what religion they are," he said.

The doctor, a well-known former political prisoner who has for years been the personal physician for opposition leader Aung San Suu Kyi, said he had treated "many monks" during 21 years at the hospital.

The facility is a rare beacon of communal harmony in a country reeling from recent religious violence that has exposed deepening national fractures as it emerges from the shadows of military rule.

Around 250 people have been killed and more than 140,000 left homeless in several outbreaks of violence since June 2012, mainly minority Muslims who have been the target of riots and a nationalistic campaign led by some radical monks.

While the spread of religious unrest has stoked tension in the country, people visiting the hospital in a multicultural quarter of downtown Yangon said differences should be put aside.

"I don't think about it. I have done business with Muslims many times in the past. I have a good friendship with them," said Tin Tin Khaing, a Buddhist, whose 57-year-old father travelled from the Irrawaddy Delta region to have a hernia operation.

The hospital started life as the result of a campaign by young local Muslims as a small dispensary in 1937, when Myanmar was called Burma and run as an outpost of British India under colonial rule.

It now has departments specialising in surgery, obstetrics and gynaecology, eyes, and psychiatry. Treatments are free to those deemed too poor to contribute, while a small fee is charged to those able to pay.

All services are desperately needed in a country where the previous junta neglected the health system as it focused on military spending.

Some international aid agencies provide limited assistance in certain areas, and there are a scattering of clinics run by the Buddhist clergy and Aung San Suu Kyi's opposition party.

But huge swathes of the impoverished population are effectively cut off from even the most basic medical help.

Chronically-underfunded government hospitals operate on a cost sharing basis, with patients charged for everything from the medicines needed to the equipment used.

According to World Health Organization data, total spending on healthcare in Myanmar was $27.9 per person in 2011.

The government accounted for just $2.9 of that -- the lowest contribution in the world. But this was actually an improvement from 2005, when the state spent just 50 US cents per capita.

Tin Myo Win, the only Buddhist department head at the hospital, said the Muslim practice of donating 10 percent of their income to charitable causes was an important source of income for the hospital, as well as paid-for treatments and international donations.

He said the hospital had long stood as a local symbol of tolerance and a refuge for those with nowhere else to go.

Under decades of junta rule, which ended two years ago, Myanmar authorities swept up hundreds of activists into the country's notorious jails, particularly those involved in mass anti-government protests in 1988 and 2007.

Political prisoners were often subjected to dire conditions, held far away from their families, treated with brutality and given no access to proper healthcare.

Many left jail in an extremely poor physical and mental state but were unable to afford treatment in state hospitals, which were also seen as hostile to the released campaigners, said Tin Myo Win.

The doctor spent three years in prison after taking part in a failed 1988 student-led uprising that also saw the rise of Suu Kyi's opposition. He has spent the two decades since his release working at the Muslim Hospital, which welcomed the detained activists.

"They don't just come here because of financial problems. It is also maybe because they believe in me. We understand each other very well. Only those who stayed in jail know how we suffered inside for food and health. The situation inside was terrible," he said.

Political reforms that have swept the country since a new quasi-civilian government took power in 2011 mean that former detainees are no longer shunned by state hospitals.

But old loyalties remain firm.

"The doctor is like my family member. We trust him, so we went to the hospital after we were released," said Kyaw Soe Naing, a five-time political prisoner who is now a close aide to Suu Kyi.

The 44-year-old said he hoped the Muslim Hospital would continue to grow and that more medical centres could follow its example.

"Whatever religion people believe in, they must receive treatment when they are sick. I want many such hospitals," he said.