Deadlock of NAST table

Hello All,

I do update NAST table by the following direct way:

1.

     UPDATE NAST SET vstat = 1 UHRVR = sy-UZEIT

      WHERE OBJKY EQ lv_nast-objky AND KSCHL EQ lv_nast-kschl AND

            ERDAT EQ lv_nast-erdat AND ERUHR EQ lv_nast-eruhr AND

            USNAM EQ lv_nast-usnam

     OR

     DELETE FROM NAST WHERE OBJKY EQ lv_nast-objky AND
           KSCHL EQ lv_nast-kschl AND ERDAT EQ lv_nast-erdat AND
           ERUHR EQ lv_nast-eruhr AND USNAM EQ lv_nast-usnam.

2. Sometime I got system dump with the following error "...Transaction was deadlocked on lock resources with another

process and has been chosen as deadlock victim..."

How do I can avoid this problem occurs ?

Thanks a lot,

Daniel.