A Toowoomba man has been charged after he allegedly followed a woman for several kilometres, hit her over the head with a rock and attempted to rape her.

Police say the assault only stopped when a nearby resident interrupted the offender, who then took off on foot.

The alleged attack on the 30-year-old woman occurred at 11pm on March 30 in Newtown, a large inner-city suburb of Toowoomba, west of Brisbane.

READ MORE: Five-year-old girl missing from Alice Springs in possible abduction

Investigators found the alleged offender, a 20-year-old man from Glenvale on Toowoomba's outskirts, in the CBD yesterday and arrested him.

He has been charged with unlawful stalking and attempt to commit rape and will appear in court today.

Anyone with information is urged to come forward to police.

Support is available from the National Sexual Assault, Domestic and Family Violence Counselling Service at 1800RESPECT (1800 737 732)