By Tume Ahemba LAGOS, Sept 18 (Reuters) - Nigeria ordered a probe on Tuesday into allegations that government officials sponsored gang fighting in the oil-producing Niger Delta last month which killed dozens of people. The city of Port Harcourt, the capital of Nigeria's top oil producing state Rivers, has been under a night curfew since Aug. 17 because of street battles between rival gangs and troops. A delegation of ethnic Ijaw leaders went to Abuja to tell President Umaru Yar'Adua that senior members of the Rivers state government, including the deputy governor, were members of the gangs involved in the fighting. "You have made very grave allegations. Put the allegations in writing and we will investigate them," Yar'Adua was quoted as saying in a statement issued by the presidency. "If it is clearly established that anyone is a party to causing the crises, he will be dealt with according to the law. We will act on whatever comes out of a thorough and just investigation," the president added. Security in the vast wetlands region, where all of Nigeria's 2.2 million barrels per day of oil is produced, deteriorated in early 2006 when militants demanding more local control of oil revenues started blowing up pipelines and abducting foreign oil workers. The attacks drove thousands of foreigners to leave the region, shut down at least a fifth of Nigeria's output and contributed to spikes in world oil prices. Political militants have ceased fire since Yar'Adua took office on May 29 to allow time for negotiations with the new government, which has promised to bring jobs, infrastructure and attention to the neglected far south. But the crisis has since degenerated into a crime wave that security forces have been unable to tame despite several heavy-handed operations. Instead, attacks by ransom seekers, armed robbers and violent gangs have persisted. Kidnappers have abducted toddlers and elderly relatives of the rich, armed robberies have multiplied and shootouts between rival gangs have killed several bystanders. There are no official figures on the number of dead, but local media reported up to 40 people were killed in fighting last month. Troops launched several raids on suspected gang hideouts on the outskirts of Port Harcourt last week using helicopter gunships, rockets and machineguns. (Additional reporting by Felix Onuah in Abuja)
