Insert BLOB via DBLINK

Hi,

I wanna insert the pdf file into the table from server B to server A via DB link.    But get the following error.  

Error

ORA-22992: cannot use LOB locators selected from remote tables

ORA-06512: at line 6

Created the table in Server A with column doc as BLOB.

Server A

CREATE TABLE cpo_docs (
  id    NUMBER(10)     NOT NULL,
  name  VARCHAR2(200)  NOT NULL,
  doc   BLOB           NULL
);

Execute the following script to insert record but error.

Server B
declare
v_bfile      BFILE;
v_blob       BLOB;
begin
  insert into cpo_docs@dblink(id,name,doc)
  values (3,3,empty_blob())
  return doc into v_blob;