Thousands of people have turned out in central London despite sleet and snow to show solidarity with women around the world in demanding equality, justice and an end to harassment.

Demonstrators chanted across from British Prime Minister Theresa May's office on Sunday with placards reading "We Are Powerful" and "Time's Up" to mark the anniversary of U.S. President Donald Trump's inauguration.

Marches supporting of female empowerment, several of them massive, also took place on Saturday.

The international events come at a time of reckoning for many men in Hollywood, media and other industries as women speak out about sexual misconduct in the workplace.

In a statement before the London march, activists said they were "coming together to pledge that we are going to make change in big and small ways."