The military government of Nigeria has sent troop reinforcements to the state of Bayelsa, in the oil-producing Niger Delta, following the declaration of a state of emergency there on Wednesday.

There are unconfirmed reports that at least twenty people have been killed in clashes between youths from the local Ijaw community and soldiers deployed to protect oil installations.

Ijaw sources say troops have been arresting Ijaw activists in the town of Yenagoa.

Many residents are reported to have fled.

A leading Ijaw group said it was demanding a significant increase in the share of oil revenues, but it was still prepared to talk to the government and oil companies.