Northern Territory Police are calling for witnesses to an alleged sexual assault in Katherine overnight.

Senior Constable First Class Brendan McLinden said the incident happened at the Katherine Information Centre carpark, where two women aged 20 and 26 were camping.

“The assault woke the pair, triggering the offender to flee the area,” he said.

They later found an amount of fuel had been siphoned from their vehicle and a jerry can was stolen.

The offender was described as a young indigenous male.

Anyone with information should contact police on 131 444 or Crime Stoppers on 1800 333 000.