The protests were against relatives of deposed President Ali Abdullah Saleh, the Socialist Forum newspaper reported.
Saleh did not live up to an agreement to have his relatives depart from the military, the report said.
Protesters in Sanaa, Aden, Dhamar, Mukallah and many other cities gathered, using the slogan, "Go away from our military," the report said.
The protesters urged new President Abdu Rabbo Mansour Hadi to rid the army of "Saleh's boys," the Socialist Forum said.
2014: The Year in Music [PHOTOS]