Houthis release kidnapped Yemen aide, three sources say
The seizure of the aide, Ahmed Awad bin Mubarak, helped plunge Yemen into political crisis, resulting in clashes between the Houthis and President Abd-Rabbu Mansour Hadi's presidential guards that prompted the president and the government to resign.
(Reporting by Sami Aboudi and Yara Bayoumy, Editing by William Maclean and Dominic Evans)