AAP leader Yogendra Yadav along with around 100 civil service aspirants were Tuesday detained while marching towards parliament protesting against the aptitude test in the entrance examination, police said.The aspirants led by the Aam Aadmi Party leader were trying to march towards parliament from Jantar Mantar, a protest site in central Delhi, around 8 p.m.They were taken to the Parliament Street police station, and were allowed to go after a few hours.The aspirants are demanding the scrapping of the Civil Services Aptitude Test (CSAT) from the examination and have been sitting at the protest site for the past several days.