Police in Zimbabwe have stopped almost 1,000 medical staff from marching to protest about the country's deteriorating health system.
The workers want the government to address staff and equipment shortages, and are calling for more pay.
Most hospitals in Zimbabwe have shut down, and fears are mounting over deaths due to lack of treatment.
Health staff say dozens of people have died from an outbreak of cholera in townships around the capital.
Pipes there have burst and running raw sewage is common.
The state-owned Herald newspaper said on Tuesday that 36 people had died from cholera and more than 430 people had been infected in one single district in Matabeleland South, near the border with South Africa.
In the capital, Harare, riot police sealed the exits of the country's main referral hospital, Parirenyatwa, to prevent staff including doctors, specialists, nurses and engineers from marching into the city centre.
Zimbabwean journalist Brian Hungwe says the workers have been told to go back to their homes or risk arrest.
The government has blamed the health sector's problems on international sanctions.
But the opposition says President Robert Mugabe's government is to blame.
Health Minister Edwin Muguti has said the sector would need about $1bn (£674m) to function properly.
Zimbabwe's central bank recently allocated about $100,000, vehicles, and 90,000 litres of fuel to improve water supplies and alleviate the cholera outbreak.