The Nigerian army has launched raids on several suspected criminal hideouts in Port Harcourt and elsewhere in the Niger Delta in a bid to flush out gangs blamed for violence in the main oil city. Security officials say several suspected gangsters are being interrogated. Gilbert da Costa has more in this report from Abuja.
The army spokesman in the region, Major Sagir Musa, confirmed the arrest of suspected gang leaders in Port Harcourt.
"Appreciable progress has been made in the areas of arms recovery and arrest of some leaders of the militants," he said. "As it is now, most of them are being interrogated with the aim of getting useful information from them. Thereafter, we hand them over to appropriate quarters for prosecution."
Ateke Tom, one of the two gang leaders held responsible for several days of inter-gang-violence in Port Harcourt has reportedly offered to surrender to state authorities. Indications are that Tom, the head of the Niger Delta Vigilante Movement, may have struck a deal with the authorities.
Criminal gangs in the Niger Delta have grown rich and powerful by stealing oil from the region's network of pipelines.
Rebels have attacked oil facilities and pipelines, killed dozens of government soldiers and kidnapped more than 200 foreign oil workers since last year.
The government has extended a curfew in Port Harcourt for a second week and troops are to remain on the streets for six months.
Major Musa says cracking down on armed groups and protecting Nigeria's oil assets would shape the nature of military operations in the region.
"Those areas that are notorious or regarded as flashpoints, we usually go there on patrol with the view to arresting the militants and getting their arms and ammunition," added Musa. "In addition, most of our national assets located in the state, like multinational oil companies like Shell, Chevron and others, we deploy soldiers there on guard duty. They are to remain there permanently."
Violence in Nigeria's oil heartland increased sharply last year when armed groups started blowing up pipelines and oil wells and kidnapping foreign workers to protest what they called neglect and corruption in the impoverished delta .