By Austin Ekeinde
PORT HARCOURT (Reuters) - Hundreds of Nigerian soldiers searched the creeks of the Niger Delta on Tuesday to flush out militants who fled helicopter and gunboat raids on their camps, the country's largest military offensive for years.
Three battalions of ground troops searched riverine communities around Chanomi Creek in the western delta thought to harbour rebels after two of their camps were destroyed at the weekend, military spokesman Colonel Rabe Abubakar said.
Some foreign oil firms have evacuated non-essential personnel from the western delta around the town of Warri for fear that militant fighters will launch retaliatory attacks on Africa's biggest oil and gas industry, security sources say.
Global oil markets have largely shrugged off the unrest as it has so far not yet had any significant impact on production.
"We have killed so many of them ... and we will not stop until we get rid of these miscreants, criminals, militants who claim to be freedom fighters," Abubakar said.
The main militant group in the region, the Movement for the Emancipation of the Niger Delta (MEND), has denied suffering heavy losses, saying only five of its fighters have been killed.
Local rights groups say the military's use of helicopter gunships has triggered a "mass evacuation" of villagers and have urged restraint by the security forces. They have asked both sides to allow humanitarian access to those displaced.
Abubakar denied civilians had been uprooted but said troops were entering communities in search of suspected rebels. He said there had been a fierce exchange of gunfire with militants in speedboats close to Chevron's Abiteye flow station.
"The indigenes of various communities in the militant-infested areas know these people ... To avoid the innocent being inconvenienced, we call on all of the people to aid in the extradition of these miscreants," he said.
The heavy military presence has made independent access to remote communities in the creeks around Warri virtually impossible since clashes broke out last Wednesday, making it difficult to verify the numbers of displaced or wounded.
The Ijaw Youth Council, an activist organisation representing the largest ethnic group in the delta, said nine Ijaw communities in the Gbaramatu Kingdom in Delta state had been raided during the military campaign in recent days.
OIL INDUSTRY ON ALERT
Insecurity has long plagued Nigeria's oil industry, with local communities in the delta angry at their continued poverty despite five decades of oil extraction by foreign firms.
MEND knocked out a quarter of Nigerian oil output in a matter of weeks when it burst onto the scene in early 2006.
Its campaign of pipeline bombings and kidnapping of oil workers since then has prevented the OPEC member from increasing production above two-thirds of its 3 million barrels per day installed capacity, costing the industry billions of dollars.
The military said it could no longer "fold its hands" after what it said were attacks last week on its soldiers, the hijacking of two vessels with foreign crew on board and threats to oil companies to evacuate their staff.
The latest clashes have centred around two camps belonging to MEND factions in Delta state -- Camp 5 and Iroko, which the military says it has destroyed. Security analysts are waiting to see whether other factions in neighbouring Rivers and Bayelsa states also now stage attacks on the industry.
MEND has said it will blockade key waterways in the region to try to prevent crude oil exports.
It also said over the weekend it had blown up two oil and gas pipelines in Delta state but there has been no independent confirmation.
Minister of State for Petroleum Odein Ajumogobia told Reuters late on Monday that oil production was running at about 1.6 million barrels per day (bpd), excluding condensate, before the latest fighting.
(Writing and additional reporting by Nick Tattersall; Editing by Matthew Jones)