By Dan Isaacs BBC, Lagos

Ethnic Ijaws want more political representation

But with a heavy army presence on the streets, the pockets of violence appear to be more localised and gunfire only sporadic.

Since the unrest began last Friday, at least 30 people have died in street battles between local militia groups, and many thousands have fled their homes.

With a tight security presence now in place in Warri town, much of the chaotic and explosive violence of the past few days appears to have abated.

Militant youths from the Ijaw and Itsekiri ethnic groups appear to have largely withdrawn back into the communities, although sporadic shooting can still be heard in some parts of town.

Oil concerns

The Nigerian Red Cross says scores of buildings have been destroyed, and many people are in need of serious medical attention.

More can be done, says spokesman Patrick Bawa, only when the situation is calmer and Red Cross teams can enter the worst affected areas.

So far, the multinational oil companies operating in the area say production has not been affected, but a spokesman for Shell in Nigeria says their office staff in Warri have been advised not to turn up to work for the time being.