ABUJA (AFP) - Nigeria on Sunday postponed parliamentary, presidential and state polls amid widespread organisational problems that have raised doubts over a crucial election period in Africa's most populous nation. Legislative elections had already been postponed once, with the delay announced hours after the vote was to begin on Saturday as materials and personnel failed to arrive at a large number of polling stations. The new dates will now be April 9 for parliamentary polls, April 16 for presidential elections. Parliamentary polls were due to be held on Monday, while the presidential vote was previously set for April 9 and state ballots on April 16. "The commission has found that the overwhelming sentiment is to further reschedule the elections," Jega said. "Requests to reschedule the national assembly elections have come from a cross-section of stakeholders, including political parties and civil society organisations. "However, rescheduling the national assembly elections would have implications for the schedule of all the other elections." There had immediately been warnings on Saturday that the two-day delay for the parliamentary elections was not nearly enough. This month's landmark polls are being viewed as a critical test of whether Africa's largest oil producer can organise a credible ballot after a history of election fraud and violence. A recently installed electoral commission headed by Jega, a respected academic, had raised hopes that the vote would be better conducted this time. President Goodluck Jonathan has repeatedly promised a free and fair election. But major problems became clear Saturday morning, with large numbers of polling places without materials and personnel. Even Jonathan's voting station was among those that did not function. Jega went on live television at around midday Saturday to announce he was pulling the plug, appearing solemn and deeply apologetic as he called the situation an "emergency." He said a vendor had not delivered materials on time, and the company had blamed air transport problems due in part to the emergency in Japan. The announcement sparked anger as it filtered to polling places, where many had waited for hours under a harsh sun. Even the polling place where the president was to cast his ballot did not function. Nigeria's election body met with harsh criticism after the initial postponement was announced on Saturday, with many questioning why Jega had signaled the day before that preparations were on course. Several rights activists and politicians labeled it a national disgrace, but some said it was better to postpone the election rather than push ahead with a poll that could never be considered credible. Following Sunday's announcement, initial reactions from two of the main opposition parties was positive, with spokesmen saying it would enable them to properly prepare for the elections.