Blueprints for 3D-printed guns, published online four days early amid last-minute attempts to ban them, have been downloaded thousands of times.

The designs were not due to be made public until Wednesday, following a ruling from the US Justice Department.

But blueprints for nine types of gun were uploaded to the Defense Distributed website on Friday.

And, on Monday, multi-state legal action was filed seeking to block the ruling that Americans could see them.

President Trump has also voiced concern via his Twitter account