Prosecutors in Russia\'s southern republic of Ingushetia have dropped criminal proceedings against the sister of the suicide bomber who attacked a Moscow airport in January. The suicide attack on the arrivals area of Domodedovo international airport on January 24 left 37 people dead and nearly 200 injured. The suspected bomber was identified as Magomed Yevloyev, 20, from a village in Ingushetia. His sister, Fatima, and his friend Umar Aushev were among a number of people arrested on charges of terrorist collaboration in February. They were later accused of illegal arms possession and bomb-making. Ingushetia\'s interior ministry told Kommersant daily on Wednesday it had dropped all charges against the pair who were released from custody in May. Aushev\'s lawyer said the two were \"fully rehabilitated.\" Chechen warlord Doku Umarov - considered to be the head of the Islamist insurgency in Russia\'s troubled North Caucasus region - has said he ordered the deadly attack on Domodedovo airport. He also claimed responsibility for the March 2010 suicide bombings on the Moscow subway in which 40 people died.