Astronauts aboard the American space shuttle Discovery have left Russia's Mir space station for the last time.

The two crews exchanged handshakes and embraces before the shuttle undocked from Mir at the end of its ninth and last visit.

The NASA astronaut Andrew Thomas, who has spent more than four months aboard Mir, is one of those returning to earth.

The next joint venture by the United States and Russia in space will be the construction of an international space station, due to start in December.