NEW DELHI: Five men pleaded not guilty on Saturday to charges they gang raped and murdered an Indian trainee physiotherapist, in a case that led to a shake-up of laws against sexual crimes after protests about a rising number of attacks on women.

A Reuters witness saw the men file into the court room with their faces covered, where lawyers in the case said they were read thirteen charges including murder, which carries a maximum penalty of death. They left after 15 minutes.

"After the judge read out the charges, the five pleaded not guilty and walked out" said A.P. Singh, a lawyer defending two of the accused, Vinay Sharma and Akshay Thakur.

Singh said the next hearing will be held on Feb. 5, when the prosecution will call three witnesses to the formal start of the trial.

A sixth person police say was part of the gang that attacked the woman and her friend is a juvenile and will be tried separately.

Police say the gang lured the 23-year-old physiotherapy student onto a bus, where they repeatedly raped and assaulted her with a metal bar before throwing her bleeding onto a highway. She died of internal injuries two weeks later.