Consulta MySql Seleccione y luego elimine

Puedes probar esto

   DELETE from circuit_u WHERE id IN ( select * from (
   select id from circuit_u
   WHERE DATE_FORMAT(cu_date,'%Y-%m-%d') = '2013-01-26'
   group by DATE_FORMAT(cu_date,'%Y-%m-%d %T'),trunk_id
   HAVING count(*) > 1 ) t
   )