The latest demonstrations in the south of the country follow similar ones held in northern Nigeria two weeks ago.

Protesters are angry at the high rate of inflation, driven largely by high food prices and the government's decision to end a long-running fuel subsidy.

On Friday, the African Development Bank warned that Nigeria could see social unrest caused by rising fuel and food prices.

In its economic outlook for this year, the bank warned that other countries, including Kenya, Ethiopia and Angola could face similar problems.