A spray-on powder that instantly seals life-threatening wounds could save thousands of lives, say scientists.

The new substance can help prevent excessive bleeding which is the leading cause of death due to injuries in war, according to a study.

The fast-acting powder that stops bleeding in just one second was developed by South Korean scientists who say it can also be applied in emergency hospital procedures.

The research team at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, which included an Army Major, created the powder that rapidly forms a strong hydrogel barrier when sprayed directly onto a bullet wound.