A man is on the run after breaking into an Alice Springs house and threatening an elderly woman while robbing her, NT Police said.

Police communications director Mark Wilton said in a statement police allege that about 11pm on Wednesday the man broke into a house on Pedler Avenue in Gillen and threatened a 68-year-old female occupant before stealing an unknown amount of property.

He said the man ran off before police arrived.

Police are asking anyone with information, particular those with dash cam or CCTV footage, to call them on 131 444 (quote reference NTP2400043528), while anonymous reports can be made through Crime Stoppers on 1800 333 000.