Some 20 satellites are trained on Haiti taking images to help in rescue efforts after the devastating earthquake there as part of a decade-old agreement to share such data in the wake of disasters.

"There is really a strong international collaboration like there was at the time of the 2004 tsunami in Asia or Hurricane Katrina," a year later, said Andre Husson of the French space agency.

The unified action is made possible by the so-called International Charter, which was declared formally operational on November 1, 2000.

Joint efforts for space data in the wake of man-made or natural disasters have been made 260 times since, Husson said, adding that the duration of the cooperation was usually between eight and 10 days.

Currently the space agencies of at least 10 countries including the United States, Britain, China, France, Japan and India, are involved in the effort, he said.

"Any demand by the International Charter overtakes commercial demands and the zone zone hit by the catastrophe takes priority," he said.

The Charter is "really global, its an area of international cooperation that is really efficient because no money changes hands," he said.

The objective is to combine images from various satellites to create detailed pictures of large areas which can then be used by teams on the ground, he said.

More than 50,000 people were killed and 250,000 injured by this week's earthquake in Haiti, which also left nearly 1.5 million homeless, a minister in the Haitian government said Friday.