Unable to drop streams rule set

Hi Oracle Support Community,

While checking invalid database objects, I have found many invalid objects of type RULE SET belonging to 'strmadmin' user. Oracle streams were configured long time before, but it is no more required. Therefore, I am trying to drop RULE SET by logging in with SYS user, but it is giving me error:

Oracle Database Server Enterprise Edition 11.2.0.4.0 on RHEL 6

SQL> BEGIN

  2  DBMS_RULE_ADM.DROP_RULE_SET(

  3  rule_set_name => 'strmadmin.<'RULE_SET_NAME'>,

  4  delete_rules  => TRUE);

  5  end;

  6  /

BEGIN

*

ERROR at line 1:

ORA-24170: STRMADMIN.<'RULE_SET_NAME'> is created by AQ, cannot be

dropped directly

ORA-06512: at "SYS.DBMS_RULE_ADM", line 158