LAGOS — Tensions have mounted between Nigerian security forces and pro-Biafra supporters, after renewed protests calling for independence and clashes targeting police.

In Port Harcourt, the capital of the southern state of Rivers, 32 people were arrested  on Thursday after two days of demonstrations and the death of one police officer.

In neighbouring Abia state, supporters of the Indigenous People of Biafra (IPOB) group targeted police in the commercial hub, Aba, and the capital, Umuahia.

The IPOB is demanding a separate state for the Igbo people who are the most populous ethnic group in Nigeria’s southeast. Fifty years ago, a declaration of Biafran independence sparked a brutal 30-month civil war.

In the latest violence, police vehicles were seen with smashed windscreens and officers fired warning shots, while there were reports of petrol bombs thrown and bonfires set to restrict movement.

A police station in Aba was burnt down on Thursday, said state police spokesman Geoffrey Ogbonna.

"We are investigating the incident but no arrest has been made," he said, but denied reports that the commissioner of police’s residence in Umuahia was attacked.

A three-day dusk-to-dawn curfew was imposed in Abia on Tuesday to prevent clashes after IPOB leaders said Nigerian troops had killed five of its members.

The army has denied the claims.

Authorities in the central state of Plateau called a similar curfew on Thursday after rumours of intercommunal attacks in the capital Jos that were a reaction to the tensions further south. Jos has in the past been the scene of inter-ethnic and religious clashes.

Abia state governor Okezie Ikpeazu said he recognised the presence of troops had been a cause of "great concern" but that they would be withdrawn from Aba and Umuahia by Friday.

"With the expected exit of soldiers from the streets, we must warn that we will not tolerate agitators and protesters taking over the streets for any reason," he added.

Local media have reported intercommunal tensions in recent days in Aba and Port Harcourt, with ethnic Hausa shopkeepers attacked by pro-Biafra supporters. — AFP