Three of Egypt's main presidential candidates have filed appeals after the election commission barred them from running, shaking up an already tumultuous race and political transition.The election commission is expected to decide on Tuesday which appeals will be reviewed, and a final list of candidates will be released on April 26, just under a month before the May 23-24 vote.This comes as the United States on Monday voiced support for "free and fair” elections in Egypt but declined to wade into a debate over the disqualification of leading presidential candidates."Our only concern is that this is a free and fair and transparent process, that it move forward in a way that meets the aspirations of the Egyptian people,” Mark Toner, the spokesman for the US state department, told reporters."But it’s not for us to comment on the political process itself,” he said.The three disqualified would-be presidential candidates are Hazem Abu Ismail, the ultra-conservative Salafi candidate, Khairat al-Shater of the Muslim Brotherhood, and Omar Suleiman, the former intelligence chief.Legal groundsThey were barred along with seven others on Saturday on legal grounds.Abu Ismail, a lawyer-turned-preacher with a devoted following, was reportedly barred from running because his late mother allegedly held dual American-Egyptian citizenship.Under a new Egyptian electoral law, the candidate, the candidate’s spouse or the candidate’s parents cannot hold any citizenship other than Egyptian.Abu Ismail has questioned why the election commission had not made public the documents that allegedly prove his mother held US citizenship.Shater’s candidacy had been challenged because of his previous criminal record.Shater, who was deputy chairman of the Muslim Brotherhood - banned under Mubarak - had been in jail on charges of terrorism and money laundering. He was granted an amnesty this year.His lawyers say that this means he is allowed to run.Lack of voter endorsementsSuleiman, Mubarak’s head of intelligence for two decades, was briefly appointed vice-president, but quit the post in February 2011 when the president resigned following weeks of mass protests against his 30-year rule.Suleiman sent his assistant to file an appeal on Sunday. Suleiman’s campaign says he was disqualified because of a problem with collecting voter endorsements, which means he has little chance of winning an appeal since he cannot submit new signatures.