Doctors in India have begun a 24-hour strike in protest at the rape and murder of a colleague in the eastern city of Kolkata.
More than one million doctors are expected to join the action – the largest in about a decade – halting many medical services across the world's most populous nation.
Hospitals and clinics across the country were turning away patients on Saturday, with only emergency cases accepted.
The strike, which began at 6am local time, cut off access to non-emergency procedures and outpatient consultations, said the Indian Medical Association.
Following a meeting with representatives of medical associations, the government urged doctors to return to work.
A 31-year old trainee doctor was raped and killed last week inside the medical college in Kolkata where she worked, triggering nationwide protests among doctors.
The incident has been compared to a 2012 attack on a physiotherapy student in New Delhi. Nirbhaya, 23, died from her injuries after being raped by six men on a bus, in a case that led to outrage across the country.
In Kolkata, thousands held a candlelit vigil into the early hours of Saturday.
“Hands that heal shouldn't bleed,” read one handwritten sign held by a protester in the eastern city.
“Enough is enough,” read another at a rally by doctors in the capital New Delhi. “Hang the rapist”, another said.
The doctor's body was found in the teaching hospital's seminar hall, suggesting she had gone there for a rest during a 36-hour shift.
An autopsy confirmed sexual assault and, in a petition to the court, the victim's parents said they suspected their daughter was assaulted by more than one person.
One man, who worked at the hospital helping manage queues, has been detained.
Kolkata police have been accused of mishandling the case and the city's High Court transferred the investigation to India's Central Bureau of Investigation to “inspire public confidence”.
A heavy police presence was seen on Saturday outside the RG Kar Medical College, where the doctor was killed, while the hospital premises were deserted, reported India's ANI news agency.
Mamata Banerjee, the chief minister of West Bengal, which includes Kolkata, has backed protests, demanding the investigation should be fast-tracked and those guilty be punished in the strongest way possible.
A large number of private clinics and diagnostic centres also remained closed in Kolkata on Saturday.
Doctors say they often face abuse from relatives of patients, with some medics assaulted. A survey by the Indian Medical Association found 75 per cent of doctors had faced some form of violence.
Protests have spread to hospitals elsewhere in the country, including in the capital New Delhi, where the All India Institute of Medical Sciences suspended non-emergency services.
In Mumbai, on the west coast, doctors at Jamshedjee Jeejeebhoy Hospital also protested.