A 17-year-old youth will appear in the Alice Springs Court today and two others are in custody in relation to an alleged sex attack on two European tourists in the town this week.

Darwin police said one of the teenagers had been charged with sexual assault while the other two 17-year-olds had been arrested but were yet to be charged.

Two women, aged 21 and 28, were asleep in their car at Mount John in Alice Springs on Wednesday morning when the vehicle was broken into and three men forced them to have sex, police allege.

Money and tobacco was also stolen from the victims before their alleged attackers fled in a stolen car.

AAP