JOHANNESBURG — The trial has resumed in South Africa of Nigerian Henry Okah, who is accused of masterminding terrorist attacks in the Nigerian city of Abuja in 2010.

Okah appeared in a Johannesburg courtroom exactly two years after the two car bombings that he is alleged to have staged killed 12 people and injured at least 36.

Prosecutors say Okah was leader of the Nigerian separatist group Movement for the Emancipation of the Niger Delta, or MEND, which claimed responsibility for the attacks.

He faces charges of engaging in terrorist activities, conspiracy to engage in terrorist activity, and delivering, placing, and detonating an explosive device. He was arrested in Johannesburg the day after the attacks.

In court Monday he sat impassively as prosecutors made their opening remarks.