The Pentagon has been accused of smuggling wounded soldiers into the United States under cover of darkness to avoid bad publicity about the number of troops being injured and maimed in Iraq. The media have also been prevented from photographing wounded soldiers when they arrive at hospital.
Records show that flights from military bases in Germany arrive in the US only at night.
Officials say this is purely the result of flight-scheduling pressures and is not a deliberate tactic to minimise detrimental publicity.
"The American public has very limited information about the real impact of this war," said Ellen Taylor, a spokeswoman for Code Pink, a peace group that has been protesting outside the Walter Reed military hospital in Washington
The Pentagon says about 12,000 troops have been evacuated from the battlefields of Afghanistan and Iraq but the actual total of injured and wounded is believed to be closer to 25,000.