[Koha] regarding bulk import and deletion

Dear Member, I imported some record in koha3 for a particular library some days ago. But problem is after deletion of those records and rebuilding zebra again its showing in OPAC and staff-client after searching . But after clicking on particular items showing error , its ok.That mean there is no record for a particular search. But why its retrieving result in first search??? So can any one please help me regarding this and which command i have to run to solve this problem, and what is actual procedure for deleting bulk records. With regards, Vijay Kumar