The Nigerian military leader, General Abdulsalam Abubakar, has warned of a deteriorating economic situation as the country prepares to return to civilian rule.

General Abubakar blamed the situation on the fall in oil revenue, which is Nigeria's main source of foreign exchange.

The government has already de-regulated the fuel market, causing big rises in the cost of petrol and cooking oil.

The BBC Lagos correspondent says the concern now is that with elections due early next year, the country's stability should not be threatened.

General Abubakar indicated that the government would take tougher measures to control the unrest in the Niger Delta, where most of Nigeria's oil comes from.