Junior doctors in India's state of West Bengal vowed on Tuesday to keep up a protest strike over the rape and murder of a trainee doctor unless their demands were met, flouting a Supreme Court deadline.

Hundreds of doctors are demanding better security at hospitals and justice for the woman, found dead on August 9 in a classroom at the RG Kar Medical College and Hospital in Kolkata, the state's capital.

The West Bengal Junior Doctors' Front said it would "consider" the court's order only if its demands were tackled by the deadline.

"Otherwise, we will understand that the government does not wish to end the deadlock," the group, which represents about 7,000 physicians in the state, said in a statement on Monday.

"In that case, we will hold the government responsible for the situation arising across the state."

The demands include better safety measures, from adequate security staff and closed circuit television (CCTV) cameras to proper patient services in government hospitals, and the removal of the city's police chief.

"We don't see a single CCTV camera being installed after the incident," said Dr Shubhendu Malik, a spokesperson for the junior doctors at the RG Kar hospital. "There is no rest room, no separate toilets for men and women."

On Monday, the Supreme Court, which took up the matter in the wake of nationwide outrage over the incident, said the doctors had until the following day to return to work, or they could face "adverse action".

Protests over the incident spread overseas on the weekend, as thousands of Indians staged demonstrations in 25 countries, including the United States and Japan, to demand justice for the woman.

Rights activists say the attack provides further evidence of the sexual violence Indian women face despite tougher laws introduced after a horrific incident of gang rape and murder in the capital, New Delhi, in 2012.

A police volunteer has been arrested for the crime and the former principal of the college has been arrested over accusations of graft.