A top U.S. military official says U.S. Marines in Haiti acted properly to defend themselves in a shooting incident that left one Haitian dead and another wounded.

The casualties occurred in an incident at a checkpoint outside the Haitian capital when Marines opened fire on a speeding vehicle.

General Peter Pace, deputy chairman of the U.S. military's Joint Chiefs of Staff, says the shooting was self-defense in the face of a threat.

"There was a vehicle that was traveling at a high rate of speed and aimed itself at the Marines," he said. "If they had not fired, they would have been hit by the vehicle."

The checkpoint where the shooting occurred is between the airport and an industrial park, where there has been massive looting since Haitian President Jean-Bertrand Aristide left the country in the face of growing opposition.

Meanwhile, Defense Secretary Donald Rumsfeld says there is no sign of either a humanitarian crisis or any mass migration by Haitians resulting from the unrest in the Caribbean country.

"There's no indication of mass migration. Quite the contrary, it's down to zero for the last three days, as I recall, of anyone trying to leave the country. Second, there's no indication of humanitarian disaster," he said.

Some 1,600 U.S. troops are in Haiti, part of an interim multi-national force that also includes 700 soldiers from Canada, Chile and France.