By Estelle Shirbon OMAGWA, Nigeria, April 13 (Reuters) - Faith Chime would like to vote on Saturday for a governor of Rivers State in southern Nigeria, but six of her neighbours were killed in gang fighting two nights ago and she fears for her safety on polling day. Rivers, Nigeria's biggest oil-producing state, is plagued by violence rooted in neglect of poor communities, political rivalries, gang turf wars and a dangerous trade in stolen crude. In Chime's village of Omagwa, a cluster of small shacks between a forest and a main road, members of two "cults" or gangs fought with guns and knives on Wednesday night, killing six people including her neighbour's teenage son. "We are not safe in the community. Those cult boys can come at any time and attack us," said Chime, a student. "I want to vote but there has to be tight security. If there is no security anything can happen," said Chime, who was cycling home with two jerrycans of water from a borehole. Like most villages in the Niger Delta, where Nigeria's 2.4 million barrels per day of crude oil exports are pumped, Omagwa has no running water and power blackouts last for days. In the last elections, in 2003, Rivers was among several states where there was evidence of significant vote-rigging. The official number of votes cast exceeded the number of registered voters in the state by 200,000. A source at the electoral body said this time, 60 percent of 1.3 million registered voters in the state were from just four out of 23 local government areas. The four areas are the heartland of the minority Ikwerre ethnic group. The candidate of the ruling party is an Ikwerre. Civil society groups have criticised the voter registration process, not just in Rivers but across Nigeria, saying it was poorly organised and open to manipulation. The electoral body has defended the register as accurate. Some Rivers residents said they were confident Saturday's gubernatorial election and the presidential poll a week later would be cleaner than in 2003 because they had registered, received their voters' card and seen no trouble. "Government has spent a lot of money to make sure there is no rigging. They are going to tighten security," said Chukwuma Okoye, a trader in electrical appliances at Rumuomasi market in Port Harcourt, the state capital. The police commissioner of Rivers said 8,000 policemen would be deployed across the state on polling day. But in Diobu, a poor commercial district bordered by slums, traders said thugs acting on behalf of candidates had already started intimidating residents. "The election cannot be clean because there are many bad ones roaming around. They will spoil the election. They can come and snatch the ballot box, they can scare the people away from the polling station," said Chima Anthony, who fixes stereos. Some politicians have used the problem of vote-rigging as a campaign argument. Billboards for the candidate of the opposition Action Congress party encouraged voters to accept bribes from other parties but still vote for him. "Chop their money, vote your spirit," said the billboards. In pidgin English, it means "take their money but vote according to your conscience". (Additional reporting by Austin Ekeinde)