A British tourist kidnapped 12 days ago in the snowcapped mountains of northern Colombia evaded his captors and was picked up by an army patrol, Colombia's army chief said Wednesday.

Mathew Scott, 19, of London, escaped Tuesday during a forced walk through the thick jungles of the Sierra Nevada mountains (search), Gen. Carlos Alberto Ospina told The Associated Press.

Scott was among eight foreign backpackers -- four Israelis, two Britons, a German and a Spaniard -- seized Sept. 12 from cabins in the archaeological ruins of Ciudad Perdida (search), or the Lost City.

Ospina said Scott appeared tired but in good health.

The general was unable to provide details on how the Briton escaped but said Scott turned up in an Indian village before a passing army patrol found him.

The army has launched a massive search for the tourists involving hundreds of troops backed by Black Hawk helicopters (search).