Tyler 'threatens police over baby shouting'

Liv Tyler reportedly threatened to call the police after witnessing a woman shouting at a crying baby.

The Lord Of The Rings star was photographed stopping her car to confront the stranger on a Los Angeles street yesterday.

According to X17 Online, she shouted: "You can't do that! I'm going to call the police. I'm going to call Child Services!"

The woman reportedly did not understand English.

The 31-year-old, who comforted the child before leaving the scene, is quoted as telling reporters: "When I saw that, I couldn't take it. I had to do something."

Tyler has a four-year-old son and is a known supporter of the UN Children's Fund.