The United Nations special envoy for refugees Angelina Jolie-Pitt told faith leaders they were in a "powerful position" to end sexual violence in conflict.

A two-day conference drawing together leaders of various faiths from across the world began today in London, organised by the Foreign and Commonwealth Office.

Mrs Jolie-Pitt, a Hollywood actress who has now dedicated her time to helping the victims of these crimes and stopping them from being a 'normal' weapon used in war, spoke of her recent trip to Iraq.

The UN's special envoy visited refugee camps for displaced Iraqis, meeting women who had escaped slavery, but had suffered rape and violence at the hands' of their captors.

"I met a young Iraqi who had been taken and kept alive as a slave and tortured with an electric drill. [Sexual violence in conflict] is violence that respects and spares no one of any religion or ethnicity.

"It is fuelled by impunity."

She said faith leaders must lift the stigma surrounding these crimes and ensure the blame for sexual violence in conflict was with perpetrators, not victims.

"We have to speak more loudly than those preaching hatred as religion. I believe we can," she concluded.

The Archbishop of Canterbury also attended the conference, thanking Mrs Jolie-Pitt for her "extraordinary" work in this area, praising the way she had placed herself in dangerous situations in order to meet the victims and therefore speak with an "authentic voice".

Archbishop Justin Welby admitted the faith community's history in this area was "questionable", so said it was vital to address sexual violence in conflict with "repentance and humility".

The Archbishop said: "The sheer chaos of the battlefield means no one knows what you are doing. Men doing terrible things to each other makes it easier to do terrible things to civilians."

He stressed the need for "moral leadership" in conflict of all faiths.

Archbishop Justin said soldiers need to understand that the consequences for these crimes will be dealt with, and that there's a better way to act. He said victims must be treated with human dignity and perpetrators must be made to see human flourishing as an "attractive alternative" to inflicting this violence.

The prime minister's special representative in preventing sexual violence in war, William Hague, told delegates at the meeting in Lancaster House that the "missing ingredient" in solving this problem –political will –had now been acquired.

But he said the biggest obstacle was the view that nothing could be done to end this rape and other forms of abuse.

All speakers stressed the prosperity of this crime depended on the impunity of bystanders.

Faith leaders were urged to adopt five recommendations, outlined in a declaration that will be signed at the end of the conference.

The need to defend values of faith and human rights, recognising the role of faith leaders in ending impunity, the role of faith leaders and communities in supporting survivors, engaging men and boys and the role of faith leaders in peace building and peace processes were stressed as key to ending sexual violence in conflict.

The conference was organise in partnership with the We Will Speak Out coalition. For church training resources and information on positive masculinities and the need to engage men and boys in this area, visit http://www.wewillspeakout.org/resource-type/church-based-resources/ and http://www.wewillspeakout.org/resource-type/menandboys/.