A group of 51 Muslim states has blocked 11 gay and transgender rights organizations from attending a meeting at the United Nations next month on ending AIDS, sparking protests from the European Union, Canada and the U.S., who say the exclusion will “only impede global progress in combating the HIV/AIDS pandemic."

Egypt, a member of the Organization of Islamic Cooperation (OIC), wrote to the president of the U.N.’s General Assembly to object to the participation of the groups, Reuters reports. The OIC also includes Saudi Arabia, Iran, Turkey, Syria and Iraq as member states.

In Egypt’s letter, a reason for the OIC’s rejection of the groups was not specified, but Samantha Power, the U.S. ambassador to the United Nations, said the groups appeared to have been blocked for their role in LGBT advocacy.

"Given that transgender people are 49 times more likely to be living with HIV than the general population, their exclusion from the high-level meeting will only impede global progress in combating the HIV/AIDS pandemic," Power wrote in a letter to General Assembly President Mogens Lykketoft.

U.N. officials told Reuters that the E.U. and Canada also wrote letters to Lykketoft in protest.

"The movement to block the participation of NGOs on spurious or hidden grounds is becoming epidemic and severely damages the credibility of the U.N.," Powers added.

U.N. Secretary-General Ban Ki-moon – caught in the middle of the battle for gay rights – has been an advocate for LGBT equality but has faced opposition from African and Arab states as well as Russia and China. In February, the countries protested six new U.N. stamps promoting LGBT equality.

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