US government warns airlines of new shoe - bomb threat

The US government has advised airlines to beware of any attempts to smuggle explosives onboard in footwear.

Homeland security officials did not indicate any known specific threat or plots, but said the warning focused on US-bound flights from abroad.

It is the second time in recent weeks that the US has warned of an increased threat of explosives on airliners.

The latest advisory comes just weeks after the US told airlines to be on the lookout for explosives hidden in toothpaste tubes on direct flights to Russia.