United Nations Special Representative of the Secretary-General on Sexual Violence in Conflict Pramila Patten on Sunday said they consistently heard about sexual violence from Rohingya survivors, including gang-rape of women by multiple soldiers.

"One survivor described being held in captivity by the Myanmar Armed Forces for 45 days when she was raped repeatedly," she told a press conference at a city hotel.

Patten said others still bore visible scars, bruises and bite marks attesting to their ordeal.

"Any actor who commits and commands or condones sexual violence against civilians must be held to account," she said.

The UN envoy said Bangladesh's efforts and humanity will be remembered in history and her office stands ready to amplify the voices of the survivors and to bridge them to the international community in order to keep a spotlight on this crisis.

"This includes keeping the spotlight of international scrutiny on the perpetrators. I want the survivors to know that they are not alone; I also want to ensure that the government of Bangladesh will not be alone in coming to their aid," she said.

The UN special envoy said they observed a pattern of widespread atrocities, including sexual violence against Rohingya women and girls who have been systematically targeted on account of their ethnicity and religion.

"A clear picture is emerging from the alleged perpetrators of these atrocities and their modus operandi. Sexual violence is being commanded, orchestrated and perpetrated by the Armed Forces of Myanmar," Patten said.

Other actors involved include the Myanmar Border Guard Police and militias composed of Rakhine Buddhists and other ethnic groups.

She also mentioned about other forms of sexual violence like forced public nudity and humiliation, and sexual slavery in military captivity.

"Several sources informed us that some women and girls have been literally raped to death," said the UN envoy.

She said some of the Rohingyas expressed their desire to return home, provided they would be granted citizenship and equal status while others said they have nothing left to return but ashes.

"The wounds are extremely raw. Women and girls dissolved into tears when recounting the extreme brutalities they both endured and witnessed," said the UN envoy.

Patten said one woman shared three concrete recommendations that made a deep impression on her.

"We want peace, we want a leader who can take responsibility for our community and we want a safe place where we can share our stories with our sisters," Patten quoted the Rohingya woman as saying.

She said all the women she spoke with wanted to see the perpetrators punished. "They all - without exception - demanded justice. And yet, not a single soldier or commander has been called to account for these atrocities."

Appreciating the role of the government, Patten said Bangladesh not only opened borders for Rohingyas but also opened their homes and hearts.

Upon her return to New York, the UN envoy will brief the UN Secretary General on the situation she observed on the ground.

Her office will compile the annual report of the Secretary General on conflict-related sexual violence to be presented to the Security Council next March which includes a dedicated section on Myanmar.

She laid emphasis on intensifying pressure on Myanmar and said the UN Security Council could also establish a mechanism to investigate the crimes.

Patten said she will also discuss the issue with the President of the International Criminal Court during her meeting soon.

Responding to a question, she said what has happened could be crimes against humanity and it could also be genocide and others have called it ethnic cleansing but she first wants to analyse the information she acquired.

The UN special envoy visited Bangladesh to better understand the patterns and trends of the sexual violence related to the conflict in Myanmar.

The Special Representative visited several field locations, including the Bangladesh-Myanmar border itself.

She met relevant Bangladeshi authorities in Dhaka and Cox's Bazar, including the security services, to discuss strengthened collaboration and coordination with the UN to respond to sexual and gender-based violence, as well as potential protection concerns arising from the unprecedented influx of Rohingyas into Bangladesh.