The US space shuttle Endeavour has left the International Space Station (ISS), carrying with it two American astronauts and a Russian cosmonaut.

They have spent more than six months in orbit, a record time for Americans in space, and are due to arrive back home on Monday.

Replacing them on the ISS are two Russians and an American who arrived on board Endeavour on 7 June.

The crew carried out three spacewalks

The shuttle's mission also involved fixing a new part on the space station's robotic arm.

"Expedition Four departing. Endeavour departing," said US astronaut Peggy Whitson, who stayed behind on the space station.

A bell on board the station was rung in naval tradition as Endeavour moved away at 1430 GMT on Saturday over the South Pacific.

The crew members held a farewell ceremony shortly before the hatches between the shuttle and the ISS were closed.

Pilot Paul Lockhart guided the spacecraft around the station to check all was well before heading for home.

The Endeavour had also delivered scientific equipment, supplies and food to the ISS.

New record

Americans Carl Walz and Dan Bursch spent a record 189 days in space. Joining them on the trip home is Russian commander Yury Onufrienko

The shuttle has settled into an orbit about 390 kilometres (240 miles) above Earth and is scheduled to land at the Kennedy Space Center in Florida at about 1700GMT on Monday.

The world record for consecutive days in space is held by Russian cosmonaut Valery Poliakov, with 437 days on Mir, the Russian space station.

During their four-month mission, Peggy Whitson with Russian cosmonauts Valery Korzun and Sergei Treschev will study the effects of prolonged spaceflight on human muscles and carry out other medical experiments.

During the shuttle's eight-day visit, astronauts Philippe Perrin, of France, and Franklin Chang-Diaz, of the US, performed three spacewalks.

One of their tasks was to repair a wrist-joint on the station's robotic arm, which they did successfully.