Egyptian doctors began a partial strike on Monday to demand better pay and working conditions, their syndicate said.
Doctors at 540 government hospitals have stopped work, but emergency and intensive-care units will continue to operate, it said.
"The strike will be in about 540 public hospitals, which is equivalent to 40 percent of the health services provided to citizens around the country," Khairy Abdel Dayem, the head of the doctors syndicate, told state media.
The strike will pile more pressure on the government which has been facing a series of state-employee actions across the country.
The doctors are demanding salary raises and a 15 percent increase in the health budget.
Medical staff are also calling for more protection at hospitals, which have been the target of frequent attacks since security broke down after the uprising the toppled Hosni Mubarak in 2011.
Representatives of the doctors union met last week with President Mohamed Morsi, but failed to agree on all the demands.
Long-running strikes, sit-ins and protests have been ongoing since the uprising, as many state employees struggle with more than one job in order to compensate for low salaries.
Labour protests and mass strikes played a large part in the uprising, but state employees in various sectors including education, transport and manufacturing say their grievances have not been properly addressed.
[Image via Agence France-Presse]