The rights organization published a 46-page report Tuesday outlining the occupation of schools by pro- and anti-government forces during the yearlong uprising that unseated longtime President Ali Abdullah Saleh.
Human Rights Watch said the practice violated international law and jeopardized an education system already ranked among the lowest in the world.
"Young people played a crucial role in Yemen's 2011 uprising, but they also suffered greatly during the conflict," said Priyanka Motaparthy, children's rights researcher at Human Rights Watch and a co-author of the report, in a statement from Beirut.
Conflict has continued unabated since Saleh's resignation in February. Yemeni Defense Minister Maj. Gen. Mohammed Nasser Ahmed survived an apparent assassination attempt Tuesday when a car bomb exploded outside the office of Yemen's prime minister in Sanaa.
The incident comes one day after Yemeni forces said they killed Said al-Shihri, the second in command of al-Qaida in the Arabian Peninsula.
U.S. counter-terrorism adviser John Brennan has described AQAP as "very, very dangerous" and "the most active operational franchise" of al-Qaida.