19 jaw-dropping photos of some of the world's toughest military training

Militaries have the challenge of preparing their soldiers for the worst of what they may face on the battlefield.

The world's militaries require their personnel to go through grueling training to equip them for the physical and psychological rigors of combat, and to make sure that soldiers who might not have prior fighting experience are still in a state of readiness.

Here are photos from around the world of some of the toughest military training imaginable.

In mainland China, paramilitary policeman face an intense regimen. Here, the policemen take part in a training session in muddy water.

Later in the training, the paramilitary police also have to crawl under fire obstacles ...

... and hone their hand-to-hand combat skills.