NAIROBI (Reuters) - Kenyan authorities banned protests in central Nairobi and other hotspots as they tried to keep a lid on mounting political turmoil in the build-up to a repeat presidential vote. The order issued on Thursday covered business districts in Nairobi, the western city of Kisumu and the port of Mombasa - the scenes of repeated demonstrations since the Supreme Court annulled the last vote in August, citing irregularities. The main opposition, which has held rallies calling for electoral reforms and the sacking of vote officials, said it would take to the streets again on Friday, and on a daily basis from Monday, despite the ban.  The protests are covered by the bill of rights in the constitution. We do not hold the protests as a favor by the State,  Dennis Onyango, the spokesman for opposition leader Raila Odinga, said. Politicians and activists from all sides have traded insults and accusations since the court ruling, raising fears of a repeat of the ethnically charged violence that killed around  1,200 people after a contested 2007 vote. President Uhuru Kenyatta, whose August election victory was annulled by the court ruling, is due to stand again against Odinga on Oct. 26. But this week Odinga announced he was withdrawing from the race, because of failure to reform the election board. The board responded that the vote would go ahead anyway with the names of Odinga and the other original candidates on the ballot paper.  At least 17 demonstrators were hospitalized on Wednesday with bullet wounds and other injuries, said medical workers in Kisumu, an opposition stronghold.  The opposition has accused the police of using excessive force while the government has accused the protesters of destroying private property .  Reuters saw footage of a crowd attacking a policeman with stones and sticks during protests in the western town of Homa Bay, near Kisumu. Marius Tum, the Homa Bay police boss, said 14 people had been arrested and would be charged with assault and participating in unlawful assembly.  Odinga s spokesman Onyango did not immediately respond to a request for a comment on the incident.   The standoff has spooked investors in the region s richest economy. The all share index on the Nairobi bourse was 0.43 percent lower at the close, amid low volumes, traders said.  In August, only Odinga and Kenyatta polled more than one percent. Three of the other candidates - Abduba Dida, Japheth Kavinga and Ekuru Aukot - told Reuters they intended to stand again.   The political battle in this country has been between the Odingas and the Kenyattas for the longest time,  said Aukot.  Voters will be looking for a neutral person who can pacify the country.  A Kenyan rights group said this week that at least 37 people were killed in protests immediately following the Aug. 8 poll. The opposition did not call any protests on Thursday. 