As President Obama tries to keep good on his promise to close the prison at Guantanamo Bay, some lawmakers are voicing apprehension about relocating prisoners to Yemen, following the Christmas Day attack on Northwest Airlines Flight 253 and recent attention that Yemen may be a hotbed for terrorists. Last month, six Yemenis were released after returning to the country because security officials determined they did not pose a threat. Obama announced Saturday that an al Qaeda affiliate operating in Yemen was responsible for the Christmas Day bombing attempt, and the U.S. and U.K. embassies there are currently closed due to ongoing threats. Sen. Joseph Lieberman (I-CT), who opposes the closing of Guantanamo, called the transfer of detainees to Yemen "irresponsible." Approximately 90 Yemenis are being held at Guantanamo, half of whom are scheduled to be sent back to their home country.