Nigerian soldiers are on the offensive in the Niger Delta, in a bid to stop a lucrative oil smuggling business. Oil theft is seen as a key catalyst of violence in the oil-rich region. Gilbert da Costa has this report from Warri.

The Nigerian military says it destroyed nearly 200 illegal oil refineries in the Niger Delta in recent weeks in a bid to re-establish control over the area that produces all of Nigeria's sweet crude. Bunkering, used in respect of oil, is a euphemism for oil theft.

A recent change in the leadership of the special military force deployed in the Niger Delta has seen the military take a more active role to intercept vessels suspected of carrying stolen oil. But a delta militant, Tom Polo, who spoke in Pidgin English, says security forces are behind the black market in stolen oil, known as "bunkering."

Polo says the military accuses people of bunkering.  But it is the military, he says, that is doing the stealing.

Analysts say 100- to 300,000 barrels of crude oil is stolen every day in Nigeria, resulting in a loss to the national economy that runs into the billions of dollars per year.

Armed groups have amassed a fortune from illicit oil sales, enough to continue hostilities for a long time to come.

The military denies complicity in oil theft, and says it is determined to track down the thieves and end the huge economic losses.

With more than 80 per cent of the country's youth population unemployed, many of the delta's agile and risk-prone youth are turning to bunkering for a livelihood.

Nigeria's crude output has been cut by at least a fifth since early 2006, when armed rebels protesting against poverty in the oil-producing Niger Delta started blowing up pipelines and production facilities, and kidnapping oil workers.