NEW YORK, May 18 (Reuters) - Unknown assailants killed two ABC News broadcast journalists in Iraq on Thursday, the U.S. news organization said on Friday. The men were identified as cameraman Alaa Uldeen Aziz and soundman Saif Laith Yousuf, it said in a statement. They were returning home from work at the ABC News Baghdad bureau when their car was attacked. Aziz is survived by his wife, two daughters and mother, and Yousuf by his fiancee, mother and brothers and sisters, ABC News said.