As two volunteers guided a man unsteady on his feet into a medical tent on the second day of a three-day pro-opposition demonstration at Freedom Park yesterday, Chan Bun Han instructed another to get the patient a bottle of water after they laid him on a cot.

A banner behind the tent noted the organisation funding the first aid effort: “CNRP, CLEVELAND, OHIO U.S.A.”

“I feel I can contribute,” Bun Han, a representative of the roughly 300-member group, said. “I do whatever I can.”

About three months ago, members of the Cambodia National Rescue Party’s Cleveland chapter flew across the globe to help their party’s campaign in the run-up to July’s national election. The only member still in Cambodia, Bun Han has expanded the group’s efforts, organising first aid tents at opposition demonstrations.

By yesterday afternoon, the ad hoc clinic had treated about 2,000 people for ailments ranging from dehydration to conjunctivitis, said Bun Han, a 67-year-old United States citizen who moved there from Kandal province amid Cambodia’s civil war in 1970. Running the clinic is costing about $500 per day, he added.

Bun Han has no medical training, but staffed the tent with volunteer medical students and pharmacists.

“In the morning, it was very, very busy,” said Panha, a 27-year-old final-year medical student who asked his surname not be identified out of fear of possible retribution from his university. “I want to help my nation.”

People who fainted or were close to fainting accounted for the lion’s share of patients who sought treatment, Panha said. But they also provided medication and vitamins to people suffering from diarrhoea, hypertension and a host of other conditions.

Many patients, Bun Han said, were not involved with the rally, but rather came to take advantage of the free medical care.

Medical student Nareth Phana, 23, said her patriotism drove her to put her training to work. “I love my country,” Phana said. “I need to help our people.”