NEW DELHI (AFP) - India's lower house on Tuesday approved a bill toughening punishments for rapists and other sexual offenders that was introduced following the fatal gang-rape of a student that sparked national outrage.

Members of the decision-making lower house of parliament gave their assent, following a seven-hour debate, to the Criminal Laws (Amendment) Bill which also contains new penalties for stalking, groping, voyeurism and acid attacks.

The legislation, which must now be approved by the nominated upper house, provides for a minimum 20-year prison sentence for gang-rape, that can be extended to life in jail.

It also provides for the death sentence if a rape victim dies or is left in a vegetative state.

"This is just a first step in a journey of 1,000 miles," said Ms Harsimrat Kaur Badal, a fiery woman MP from the regional Shiromani Akali Dal party, in the final moments of the debate.

The bill's approval by the lower house came four days after a 39-year-old Swiss cyclist was gang-raped in the Indian state of Madhya Pradesh in an attack that observers said underscored the risks that women face in the country of 1.2 billion people.

It also came on the day a female British tourist suffered leg injuries when she jumped out of a hotel window over fears of being sexually attacked in the Indian city of Agra, home to the Taj Mahal.

Under the existing law governing sexual offences, a rapist faces seven to 10 years in jail.

A government-appointed panel in January recommended stiffer laws after a 23-year-old student was gang-raped by six drunken men and attacked with an iron bar on a bus on December 16. She died nearly two weeks later of massive internal injuries.