A group of 11 prominent charities is preparing a letter calling on the US to remove logos on American-funded assistance in Pakistan. The letter, signed by charities including Save the Children, Oxfam, and World Vision says that such "branding" of aid jeopardises their neutrality. They say that this is especially dangerous in a country with numerous anti-American militants. The letter will be delivered later this week in Washington, officials say. 'Highly sensitive' It says that there are "strong indicators" that branding will attract violent attacks for both economic and ideologically-motivated reasons". The US insists that branding is important in non-sensitive areas of Pakistan The letter will be sent to the US government aid agency, USAID, by the InterAction group, a coalition of more than 160 humanitarian organisations working around the world. International charities have for several years refrained from using their own logos in Pakistan because of the security risk. However the US government, through USAID, requires non-governmental organisations that receive funding to "brand" aid with the agency's handshake logo and the words "from the American people" in local languages. USAID have yet to comment on the proposed letter, but a blog written by the organisation's Mark Ward says that it is "highly sensitive to the risks of branding in environments where one's association with foreigners can turn a humanitarian worker into a target". The blog says that in those parts of Pakistan where security is not an issue, "we continue to require branding on our aid". "Branding is not just required by law; it ensures transparency when America provides aid. We believe that the people we help have a right to know where their assistance is coming from," Mr Ward wrote. Aid agencies say that the safety of partners and beneficiaries is at stake The letter is being sent amid fears for aid workers posed by the Taliban in Pakistan and Afghanistan. On Friday Scottish aid worker Linda Norgrove was killed in Afghanistan as US special forces tried to rescue her from kidnappers. Save the Children Pakistan representative Mohammed Qazilbash told the BBC that the danger posed by such logos was especially apparent when displayed on rebuilt schools, reconstructed buildings, health posts, T-shirts, caps and vehicles. "It is essential that the US considers this because the safety and security of our beneficiaries and partners in Pakistan is at stake," he said. "We are currently negotiating an alternative branding strategy with the US authorities," he said. In August the UN said it was reviewing security measures for its staff in Pakistan, after the Taliban said the presence of foreign aid workers in the country was unacceptable. There have been no attacks in Pakistan since devastating floods this summer.