UNITED NATIONS - Five UN agencies have banded together to call for urgently addressing gender-biased sex selection favouring boys, a common practice in many parts of South, East and Central Asia that they say fuels a culture of discrimination and violence. Sex selection in favour of boys is a symptom of pervasive social, cultural, political and economic injustices against women, and a manifest violation of womens human rights, says a statement issued by the agencies, which have reviewed the evidence behind the causes, consequences and lessons learned regarding son preference.