New Delhi, Dec 19 (IANS): Congress president Sonia Gandhi Tuesday expressed horror at the gang rape of the 23-year-old girl and asked Union Home Minister Sushilkumar Shinde and Delhi Chief Minister Sheila Dikshit to take urgent action to improve security of "daughters, sisters and mothers".

Gandhi conveyed her message in separate strongly-worded letters to Shinde and Dikshit.

In her letter to Shinde, Gandhi said the monstrous crime deserves not only universal condemnation but also the government's most urgent attention.

She said it was imperative that police and other agencies concerned are sensitised to the danger and that "our daughters, sister and mothers face everyday".

"Security agencies must be motivated to deal with this menace. I hope you will initiate immediate action to remedy the situation," she wrote to Shinde.

"It is a shame for all of us who are responsible for security of our cities that a young woman can be raped in a moving bus in the capital city and flung on to the street," the Congress president added.

In her letter to Dikshit, Gandhi said there was an urgent need to demonstrate "our sncerity and determination" in improving security of women.

"I would urge you to take whatever steps are necessary to undertake community action to strengthen law and order and to step up vigilance to protect women," Gandhi wrote.

The Congress president began the letter by saying that "we are horrified at the incident concerning the young woman".

"It is a matter of shame that these incidents recur with painful regularity and that our daughters, sisters and mothers are unsafe in the capital city. Such violence and criminality need not only to be condemned, it calls for a concerted effort to fight it."

Gandhi told Dikshit that the Delhi chief minister had her and her party's support in efforts to improve security for women.

Earlier, the Congress president visited Safdarjung Hospital and met doctors treating the girl.

Gandhi discussed the condition of the girl, who is on ventilator support, with attending doctors and hospital authorities.

The brutal rape and torture occurred Sunday night when the girl and her friend boarded a private bus at Munirka in south Delhi to go to Dwarka in west Delhi after watching a movie. The woman was beaten up and raped by at least six men inside the bus. Four accused have been arrested.