There is only one speciesof wild horse left in the world: the equus ferus przewalskii, or Przewalskii Horse. Native to the Gobi Desert and Central Asia, the Przewalskii is now an endangered species and many are kept in zoos, however, several hundred do still exist in the wild in Mongolia having been recently reintroduced.
What many people assume to be wild horses - such as the Mustang - are in fact feral horses; a feral horse is a species of horse that was domesticated in the past and escaped to form herds which now exist in the wild so while they are untamed, some of their instincts and genetic code will have been moulded in the past through selective breeding by the breeders of their ancestors.
No horses live in the jungle that I know of, although, it could be possible that one or two have escaped and do - but not in any great number.
Hope it helps!