Three girls approached by men in Sydney

Three girls have been approached by men who tried to entice them into their cars in separate incidents in Sydney's outer west.

A man approached a 13-year-old girl at a bus stop on Cobham Street, Kings Park, shortly before 8am (AEST) on Thursday.

Police say the man opened the car door of his olive coloured sedan, and offered the girl a lift.

She refused and later alerted teachers at her school.

The man has been described as being aged in his 40s, with grey hair, a moustache, and fair skin.

Seven hours later, a man in a white Hilux ute offered a lift to two 10-year-old girls standing at the corner of Mimosa and Prairiewood Roads, Prairiewood.

The girls walked away and the grey haired man drove from the scene.

He's described as being Caucasian, about 60 years old, with a solid to fat build and using a walking stick.

Police don't believe either incident is linked and they are urging parents to warn their children not to accept lifts from strangers.