The Delhi High Court on Wednesday issued notice to the accused in five different cases relating to the 1984 anti-Sikh riots, asking them why the cases against them should not be re-opened.The bench of Justice Gita Mittal and Justice Anu Malhotra issued notice to the accused in the cases in which all of them had been acquitted in 1986.Those issued notice include ex-Councillor Balwan Khokkar, former MLA Mahender Yadav and Ved Prakash.The court directed the Central Bureau of Investigation to trace the complainants and serve them notice to appear before the court on April 20.The court took suo motu cognisance of the five cases, observing that key eyewitnesses were not examined and cases were closed "very rapidly" without proper investigation and trial.The bench passed this order after taking note of the trial court judgements passed in 1986 in the five cases.The trial court records were placed before the high court by the CBI during the hearing of another 1984 riot case, in which the acquittal of Congress leader Sajjan Kumar has been challenged by the probe agency.