Cameroon\'s security forces stepped up their presence in the country\'s main towns ahead of Sunday\'s presidential election, which incumbent Paul Biya seems assured of winning. Campaigning for Cameroon\'s presidential election wound up amid general indifference Saturday, with the opposition complaining that Biya has weighted the electoral system in his favour to ensure victory. The 78-year-old veteran, in power since 1982, ended his campaign with a rare appearance Saturday, this time in the coastal town of Kribi, in his native south. It was only the third time the leader had made a public appearance during the campaign. John Fru Ndi, generally considered his main rival, staged a large rally Saturday afternoon in the capital Yaounde before heading for his main power base in Bamenda, the main town in the northwest. The opposition complains that Biya\'s control over the electoral system is so complete that there can be no doubt about the results. On paper, seven million people are eligible to vote Sunday. But although voting cards were still being handed out Saturday, one electoral officer in Yaounde said: \"Not many people are coming to take their cards.\" Speaking on condition of anonymity, he added: \"In a week, we have only been able to distribute 600 cards, when we have received 1,500 of them.\" In Douala meanwhile, several people eligible to vote said they still had not received their voting cards. \"I did all the registering process and they have still not drawn up my card,\" complained one man, who would only identify himself as Jean-Paul. More than 6,000 election observers have been accredited to monitor voting at more than 24,000 voting stations across the country -- and some abroad. But turnout for the vote is expected to be low. The authorities have stepped up security in the main towns and cities in case of trouble. On September 29, two grenades were found in a voting station at Elecam in the Limbe region in the southwest of the country. The same day, according to local press reports, men in military fatigues fired shots at the bridge over the Wouri river at Douala. The markets were busy on Saturday as people stocked up on food, in anticipation of possible post-election unrest. \"My aunt is getting ready to go to market to do the shopping,\" said 25-year-old Raissa. \"We don\'t know if things are going to go well or not tomorrow,\" she added. There were food shortages in February 2008, as people rioted against the high cost of living and moves by the president to end the limit on presidential mandates -- reforms that were passed a few weeks later. Official figures put the death toll during the unrest at 40; rights groups said the true figure was 139. France\'s consulate advised its citizens living in Cameroon to avoid voting stations, to stay away from crowds and only to go out if strictly necessary. Rap star General Valsero, an outspoken critic of Biya, even called on people to return blank voting slips, saying none of the 23 candidates deserved their support. \"The opposition can\'t get itself together,\" he said, accusing the leading figures of selfishness for having failed to unite their forces.