CBI will challenge before Delhi High Court the acquittal of Congress leader Sajjan Kumar in a 1984 anti-Sikh riots case by a city court as it has found "strong grounds" which could form basis of its petition.

CBI sources said here today that the agency is likely to wait till the court pronounces its verdict on the quantum of sentence for those found guilty in the case.

District and Sessions Judge J R Aryan had on April 30 acquitted Kumar in the 29-year-old case in which he was accused of murder and of instigating a riotous mob that killed five Sikhs in Delhi's cantonment area.

Five others -- Balwan Khokkar, an ex-councillor, Mahender Yadav, an ex-MLA, Kishan Khokkar, Girdhari Lal and Captain Bhagmal -- were convicted for their involvement in the riots that had broken out after the assassination of the then Prime Minister Indira Gandhi on October 31, 1984.