By Andrew Walker
BBC News, Warri
For the past 13 days the Nigerian military has been mounting an offensive in the swampy creeks of the Niger Delta, pursuing oil militants who kidnapped 15 sailors, 18 soldiers and hijacked a petrol tanker belonging to the national oil company.
They say the continuing military action is an attempt to rescue their men or confirm if they are dead.
The militants started it, they say, and the military is just reacting, according to commander Gen Sarkin Yakin Bello, whose name means "lord of war" in the northern Hausa language.
But security and diplomatic sources have told the BBC the military action in Delta State is part of a new "get tough" approach which has been on the army's drawing board for months in an attempt to deal with key militant leaders from the Movement for the Emancipation of the Niger Delta (Mend).
The clock is ticking on the offensive, as it is disrupting business, and may begin to have a bad effect on Nigeria's already depressed oil industry.
The military action could backfire and stir up militancy in the western Niger Delta, observers say.
It could also spark ethnic conflict in a race to secure lucrative patronage from government and business in the Delta.
Stories are emerging from the area of military brutality against civilians, as soldiers move through villages looking for guns and weapons.
Groups representing the Ijaw people who live in the area have issued alarming numbers for those killed or chased from their homes.
The military has denied access to journalists so far.
But the Nigerian Red Cross has told the BBC they went to several villages in the creeks and saw a few burned houses, but not the total destruction those fleeing described.
Those who fled into the bush have been creeping back to their homes at night and then leaving again at first light, the Red Cross's Ovocity Egboworo said.
"The biggest problem they are facing is a lack of food, as no supplies have been able to get up there for some time now," he said.
Other international aid agencies have decided not to travel to the region for the time being, unconvinced that the humanitarian need outweighs the risk of going into the active conflict zone.
It is certain that this is the largest military operation against the militants since the rise of the armed conflict in 2006.
Mend leader Government Tompolo is now on the run
They are attacking fighters loyal to the man known to be the regional commander, and suspected to be the overall military leader of Mend, Government Tompolo.
Mr Tompolo has in recent years established himself as the major powerbroker in the area.
Local businessmen say he is the point man for the leaders of the Ijaw community, funnelling money from government patronage and lucrative contracts and members of his family and close circle hold key government positions.
If a company wants to move anything in the oil creeks of Escravos and Forcados, home to a great deal of Nigeria's oil industry, they must pay Mr Tompolo's "boys" for protection.
The militants also make money stealing crude and selling it through bunkering syndicates, an organised crime operation that has links to Nigerian politicians, military figures, and connections to drug and gun runners, analysts say.
Before the recent offensive violence against oil infrastructure was actually down, as the militants had reached terms with the state government and the oil companies.
The military action seems aimed at dislodging Mr Tompolo from this powerful position.
Mr Tompolo is on the run from his base, rumoured to be either in Cameroon, the Nigerian state of Akwa Ibom, or lying low in the Delta State city of Warri, depending on who you talk to.
But leaders from his Ijaw ethnic community have apparently withdrawn their support for him.
Ijaw elder Chief Edwin Clark, 76, told the BBC he would not shelter Mr Tompolo.
"He is not a monster, but if he came to me I would hand him over to the authorities," said Mr Clark, who has decided to get out of the region for a couple of weeks.
Mr Tompolo still commands large military resources, and while it remains to be seen if he can return to his plum position, it is clear he is not prepared to go without a fight.
But Mr Clark says it seems like the government is serious about tackling the militants this time.
Last year the military was given millions of dollars to spend on equipment for fighting in the Niger Delta.
Soldiers of the JTF review weapons allegedly seized from a Mend camp
A report leaked outlined possible military scenarios, including the one currently unfolding.
There was also a large military exercise several months ago in Ondo State where the military Joint Task Force (JTF) practised the tactics it would need to fight militants.
Following a briefing by Nigeria's Foreign Minister Ojo Maduekwe, diplomatic sources told the BBC they came away with the impression the militant attack that triggered the current operation had simply put in motion an existing plan.
But security sources say the military will have to capture large amounts of weapons for this offensive to be a success, as there is no way they can kill all the militants.
Nothing is moving on the creeks now, and militants have continued to attack pipelines shutting in 100,000 barrels per day.
So far the military has shown journalists a heap of rusted antique shotguns and a few buckets of bullets.
'Not the end'
A former adviser to both ex-Nigerian President Olusegun Obasanjo and his successor Umaru Yar'Adua on the Niger Delta told the BBC he was afraid the military action would make the situation worse in the long run.
"Removing Tompolo will not be the end of it," said Rev Stephen Davis, Canon Emeritus at Coventry Cathedral's reconciliation ministry, who recently wrote a report on the possibilities of peace in the Niger Delta.
This would open a position other leaders would be prepared to fight over, he argued, raising the spectre of gang warfare in Delta State.
It also risked inflaming ethnic tensions between Ijaw and another Delta State ethnic group, the Itsekiri.
The two fought a war between 1997 and 2002, and Mr Tompolo's hold on government patronage came as a direct result of the Ijaw victory.
According to Rev Davis, the Mend leader is not the root of the problem, but a symptom of the lack of governance in the Niger Delta.
"Tompolo is a toll-gate keeper," he says.
"The real ones driving this conflict are the ones who built the road."