The Delhi high court has directed the Union government to ensure strict compliance of a ban on use of cellular mobile phones in aircraft. "The authorities must ensure that there is no use of mobile phones when a plane is in motion,' stated a division bench. "If there is any aberration, it should be recorded and strict action must be taken,' the bench added. The court's order followed a public interest litigation , which alleged that on May 12, 2000 politician Prabhu Nath Singh phoned civil aviation and tourism minister Sharad Yadav from his mobile phone. Following this, Yadav issued an oral order for change of the flight's schedule. Besides, the court said that use of mobile phones was also harmful as radioactive waves emitted by them can interfere with electrical and communication mechanisms of an aircraft's control panel.