Stored procedure causes ORA-0000

We have a stored procedure that truncates several tables. However, running it generates ORA-0000 errors on all tables, yet the tables appear to be truncated (but I'm not 100% sure there were rows in these tables to begin with):

truncated FABBRCC :ORA-0000: normal, successful completion
truncated FABCKMC :ORA-0000: normal, successful completion
truncated FARCKMC :ORA-0000: normal, successful completion
truncated FBRATHC :ORA-0000: normal, successful completion

What is causing these errors? Should I just ignore them, or does the procedure need to be altered? The procedure looks like this:

PROCEDURE TRUNC_FIMSMGR_TABLES
as
procedure one_table(tab_name varchar2) is
cursor_id integer; -- holds cursor id
return_value integer; -- holds call return value
str varchar2(150); -- string to hold DDL statement
BEGIN
cursor_id := dbms_sql.open_cursor;
str := 'truncate table fimsmgr.' || tab_name;
dbms_sql.parse (cursor_id, str, dbms_sql.v7);
return_value := dbms_sql.execute(cursor_id);
dbms_sql.close_cursor(cursor_id);
commit;
DBMS_OUTPUT.PUT_LINE
('truncated ' || tab_name || ' :' ||
sqlerrm );
EXCEPTION
When Others then
DBMS_OUTPUT.PUT_LINE
('error ' || tab_name || ' :' ||
sqlerrm);
dbms_sql.close_cursor(cursor_id);
END;
BEGIN /* Main Procedure */
DBMS_OUTPUT.PUT_LINE
('TRUNCATE FIMSCOL TABLES' || to_char(sysdate,' DD-MON-YYYY HH24:MM'));
one_table ('FABBRCC');
one_table ('FABCKMC');
one_table ('FARCKMC');
one_table ('FBRATHC');