A dog has saved its owner from an attempted rape during an evening walk in a park.
The woman, 36, was with her pet in Winnersh, Berkshire, at 18:00 GMT on Thursday when a man approached her from behind, said police.
The man pulled her to the ground behind Dunstans Drive and tried to remove her clothes when her dog became "aggressive".
The man then "fled the scene", according to Thames Valley Police.
The force is appealing for witnesses and has put a "scenewatch" at the park.
Police have described the incident as an attempted rape and said it was "a very distressing and traumatic experience for the victim".
The man is described as in his 30s, tanned, with dark hair and a clean shaven face. He was wearing a black hooded top and black or navy jogging bottoms.
Det Ch Insp Matt Stone said: "I understand that people in the area will be very concerned about this incident, but I would like to reassure them that we have begun a full and thorough investigation."
He added that residents could expect an "increased police presence" in the area.