Gabon's President Omar Bongo, Africa's longest serving leader, said on Saturday he would stand for another 7-year term of office in presidential elections due by the end of December, Reuters reports. Bongo, who has ruled the oil-producing Central African country since 1967, announced his candidacy for the polls in front of thousands of supporters at a youth meeting in the capital Libreville. "With all these requests, with all that I have heard, I say to you simply: Yes, I accept," Bongo said to roaring applause. Bongo changed the constitution to remove any limits on presidential terms in office, a move also attempted by a number of other African presidents which has been criticised by United Nations Secretary-General Kofi Annan, among others. His opponents accuse him of being authoritarian, renewing their complaints after he ordered the Interior Ministry last month to stop them leaving the country in reaction to criticism from opposition politicians abroad. Officials have said no new passports will be issued to opposition leaders while those already holding them would have them withdrawn if they tried to leave the country. Bongo, 69, ordered the ban after former political ally Zacharie Myboto said in interviews with French media that the electoral register for December's presidential poll had been fraudulently inflated. He was also believed to have been irritated by a protest organised outside the United Nations last month, staged as he was addressing a summit, by a U.S.-based group of Gabonese exiles called "Bongo must leave".