Mexican prosecutors have questioned a former mayor of Mexico City about his involvement in the deaths of over 30 students in 1971.
At a heavily guarded hospital in the northern Mexican city of Monterrey, former mayor Mr Alfonso Martinez Dominguez sat in a wheelchair as officials read him a list of 95 questions.
Protesters outside the hospital carried a block-long banner with the word "Justice" repeated on it.
Mr Martinez was removed from his post as mayor shortly after police violently broke up a June 10th, 1971, student march. He has said he was not responsible for the deaths.
President Mr Vicente Fox named a special prosecutor last year after the government's National Human Rights Commission confirmed at least 275 "disappearances" in the 1970s and early 1980s.
Mr Fox, whose election ended the Institutional Revolutionary Party's 71-year rule, has promised to end government-sponsored corruption and violence.
Human rights groups charge that Mexico City's government, under the supervision of the federal government, recruited, trained and paid a paramilitary group called the "Falcons" to kill political activists.
AP