NEW DELHI (AP) — An Indian court has convicted a former politician of helping incite violence during anti-Sikh pogroms that left thousands of people dead.

The Delhi High Court on Monday reversed an earlier acquittal of Sajjan Kumar in the 1984 riots, which broke out after then-Prime Minister Indira Gandhi was killed by her Sikh bodyguards.

The 73-year-old Kumar, then a leader in Gandhi's Congress party, was accused of inciting a New Delhi mob to kill a Sikh family. He was sentenced to life in prison. He has been ordered to surrender by Dec. 31. More than 3,000 Sikhs were killed just in New Delhi.

A handful of other officials have been imprisoned for the anti-Sikh violence.

India's criminal justice system moves painfully slowly, with powerful suspects often able to dodge prosecution.