How to directly query other user tables
Just in case somebody else needs, I am posting the solution I used. Instead of using fromuser and touser options, I used remap_schema option: 

&gt; impdp user1/password DIRECTORY=backup_dir DUMPFILE=Dump.dmp FULL=Y
&gt; remap_schema=user2:user1


Also, if the tablespaces are different, they must be remapped, too:

&gt; impdp user1/password DIRECTORY=backup_dir DUMPFILE=Dump.dmp FULL=Y
&gt; remap_schema=user2:user1 remap_tablespace=table2:table1