A pledge by US President Barack Obama to tighten gun control laws has led to firearms sales soaring across America.

Manufacturers are struggling to keep up with demand, and many gun shops running low on stock as the US public buys weapons in anticipation of tighter controls.

On the campaign trail last year Mr Obama proposed restoring a Clinton-era ban on several types of military-style semi-automatic rifles and high-capacity magazines, as well as background checks for buyers at gun shows, and other "common-sense measures".