Updated

Nigerians are voting for state governors and assemblies in elections in which the opposition hopes to make gains following its victory that unseated President Goodluck Jonathan two weeks ago.

Tensions are high in the south where close contests are expected in Lagos, Nigeria's financial heart and wealthiest state, and oil-rich Rivers State.

Witnesses say agitators set a polling station ablaze in Rivers, protesters firebombed a police car and opposition supporters marched peacefully in another area where they charge Jonathan's party is attempting to rig the vote. The witnesses insisted on anonymity for their safety.

Igbo people in Lagos have been agitated since the traditional Yoruba leader threatened to kill them if they do not vote for his opposition gubernatorial candidate.

The opposition holds 14 states and Jonathan's party 21.