NEW DELHI (Reuters) - The alleged rape of 5-year-old girl by a male neighbor in the Indian capital New Delhi triggered a protest march on Friday to a city hospital by her relatives and political activists, reawakening concerns about safety for women and girls.

Despite a public holiday, several hundred people gathered outside a municipal hospital in eastern Delhi, where the girl was admitted for treatment on Thursday.

They demanded better law enforcement and chanted slogans on gender rights, television reports showed.

The girl's rape, which left her in a critical condition, revived memories of the brutal gang rape by five adult men and a teenaged boy of a 23-year-old physiotherapy student on a bus on December 16 in New Delhi. That woman died of her injuries.

B.N. Bansal, a doctor from the Swami Dayanand Hospital, told reporters, that the young victims had undergone an operation.

"The next 48 hours will be crucial for her."

The girl, whose parents work as laborers and live in a slum in the outskirts of Delhi, went missing from home on April 15, according to Manish Sisodia, an official of the Aam Aadmi Party which organized Friday's protest.

She was found with bruise marks on her body in the suspect's house in a semi-conscious condition on Thursday by police after her parents had registered a complaint, media reports said.

The suspect, who fled, allegedly held the girl hostage for three days during which he raped and tortured her.

Prime Minister Manmohan Singh was deeply disturbed by the incident, a statement from his office said.

The unprecedented protests by thousands of people across India after the December assault had forced Singh's government to pass tougher laws to fight gender crimes in March.

But activists on Friday said the laws were not enough to deter sex offenders in India's largely patriarchal societies.

"If you thought just bringing in a new law will stop crimes, your are wrong. They will reduce, but won't stop. You need community policing to stop these crimes," activist Kiran Bedi told an Indian TV channel.

(Reporting By Satarupa Bhattacharjya and Sankalp Phartiyal; Editing by Michael Roddy)