JOHANNESBURG (Reuters) - A South African court sentenced suspected former Niger Delta rebel leader Henry Okah to 24 years in jail on Tuesday for masterminding two deadly car bombings in the Nigerian capital in 2010, officials said.

The bombs killed at least 10 people during Independence Day celebrations in Abuja. Okah was convicted in January on 13 counts, including conspiracy to commit terrorism and detonating explosives.

Okah, who denies any leadership role in the Movement for the Emancipation of the Niger Delta (MEND), moved to South Africa after Nigeria issued an amnesty for members of the guerrilla group in 2009, lifting charges of gun-running and treason against him.

The South African court tried Okah under counter-terrorism laws that cover crimes committed outside the country.

"As far as this trial is concerned, it is more as if I faced a lynch mob," he told Reuters a few weeks before being sentenced. "I don't have control of anybody. I can't speak for whoever is going around the media making threats."

MEND's attacks on oilfields and pipelines across the swampy region that is home to Africa's biggest oil and gas industry cost Nigeria $1 billion a month in lost revenues at its peak, according to the central bank.

(Reporting by Jon Herskovitz; Editing by Ed Cropley/Ruth Pitchford)