(AGI) Baghdad, Sept 28 - Shiite rebels in Yemen, led by ImamAbdel Malik al-Houthi, have signed part of a security dealundersigned by all the country's political parties, requiringthem to withdraw from Sana'a. They had refused to sign thatparticular part of the document last Sunday. Under the terms ofthe agreement, they are required to withdraw their troops fromthe cities of Amran and al-Jawf, north of Sana'a. It also callsfor the formation of a unity government, to which the Shiiteswill also belong. There had been concerns over whether or notan agreement would be reached. (AGI) . .