By Dan Isaacs BBC, Lagos

The Nigerian oil industry is facing another significant set-back, with workers from the Anglo-Dutch multinational, Shell, going on strike in the Niger Delta.

Oil production has been affected by unrest

They are protesting at feared job cuts as the result of a new restructuring plan for the company.

The oil industry in Nigeria is already suffering from major losses in output over the past months as a result of community unrest in the oil-producing regions of Nigeria.

But this latest problem may just turn out to be a simple misunderstanding.

Staff locally employed by Shell strongly believe that a newly-rolled-out "exploration and production globalisation plan" will lead to job losses.

Posts, they believe, will be filled by ex-patriate staff.

This, says Shell, is an unfounded rumour and they say that this will be explained clearly to the white-collar union, Pengasson.

Production

Shell have made it quite clear production has not so far been affected by this latest dispute.

But clearly the company is under a great deal of pressure at the moment as a result of local unrest and direct threats against oil installations by local militia groups over the past few months.

A substantial part of their operation in the western Niger Delta have already been shut down, and staff have been evacuated for their own safety.

And the government has now sent a large army contingent to the area to quell the unrest.

At a conservative estimate, at least 200,000 barrels are currently being lost from production every day in Nigeria as a result of the instability.

And industry analysts believe that a further 100,000 barrels are lost each day due to theft from the pipelines.