How to open a new tab in GNOME Terminal from command line?

I'm using Ubuntu 9.04 x64 and when I write: gnome-terminal --tab At the terminal, I expect it to open a new tab in the same terminal window. But it opens a new window instead. I found out that its intention is to open a new tab in a new window, i.e., if I write: gnome-terminal --tab --tab It will open a new window with two tabs. So, the question is, how can I open a new tab in the _current_ window using a command in `gnome-terminal`?