Hundreds of thousands of people poured into the US capital on Saturday to march in opposition to President Donald Trump, a day after the Republican took office, as sister demonstrations took place in cities across Africa, Asia and Europe.

Women and men of all ages took to the streets of Washington, DC, rallying around issues like women's rights, reproductive rights and immigration.

The march was supposed to be along the National Mall, the stretch of parkland that runs from Congress to the White House. But it spilled onto Pennsylvania Avenue, the street where the new president and property tycoon now lives, and where his Washington-based hotel is.

Protesters held signs like "Women's rights are human rights", "Break down walls, don't build them", and "Hell hath no fury as a nasty woman scorned", referencing the time Trump called his opponent, Hillary Clinton, a "nasty woman" during a debate.

Sophie Walker, the leader of the Women's Equality party, told Al Jazeera that protesters had gathered in a show of unity.

"We are here to protest the hate and the division that Donald Trump puts forward as politics," she said.

"We are here to march against the rising xenophobia in this country. We're here to march against the normalisation of racism and misogyny and sexism."

Many participants wore knitted pink cat-eared "pussy" hats, a reference to Trump's admission to having committed sexual assault in a video that was made public weeks before the election.

In that video, Trump said he grabbed women by the genitals without their consent, sparking outrage.

Monica Moran, who travelled to the protest with her daughter from Massachusetts, said she was worried Trump would cut funding for the Violence Against Women Act, a law that provides wide-ranging services to victims of domestic violence and sexual abuse, among others.

"We know one in three or one in four women will face domestic violence in their lifetime and we know these programmes are working. A lot more women are going to get killed if [Trump] doesn't fund this," she told Al Jazeera.

OPINION: Why women marched on Washington

The protest illustrated the depth of the anger in a deeply divided country that is still recovering from the scarring 2016 election campaign season.

Although authorities in Washington, DC, do not release crowd counts, organisers told AFP news agency they estimated turnout at one million - quadrupling initial expectations - with huge crowds joining sister marches around the country.

More than half a million people also took to the streets of Los Angeles, according to police there, and a similar number gathered in New York. Other marches took place in Chicago, Dallas, San Francisco, Denver, St Louis and elsewhere.

The #WomensMarch in downtown St. Louis! This is what democracy looks like. pic.twitter.com/mzb5xMZUKC — Antonio French (@AntonioFrench) January 21, 2017

Trump has drawn the ire of liberals, leftists and other progressives for sexist comments and xenophobic language, while many abroad are worried over his inaugural vow on Friday to put "America First" in his decision-making.

Global protests

Demonstrations against Trump's discriminatory rhetoric were also held in Australia, the UK, Germany, Japan and France, and others.

In Kenya, hundreds of protesters in Nairobi's Karura Forest waved placards and sang American protest songs.

In Sydney, Australia's biggest city, about 3,000 men and women gathered for a rally in Hyde Park before marching on the US consulate downtown, while organisers said 5,000 people rallied in Melbourne.

In Japan, hundreds of people joined protests in Tokyo, including many American expatriates.

Protest organisers in the UK said more than 100,000 packed London's Trafalgar Square, chanting "dump Trump" and waving banners demanding equal rights.

"Make bigotry wrong again" and "We shall overcomb" were among the banners held aloft.

Around 2,000 people marched in Vienna, according to estimates by the police and organisers, but sub-zero temperatures quickly thinned the crowd to a couple of hundred.

In Stockholm, the Swedish capital, several thousand people gathered to express support for women's rights and human rights, and in solidarity with the demonstrations in the US.

They marched to the US embassy, some carrying placards that read "Tiny hands off the nukes", "When they go low, we go high", and "Love not hate makes America great".

A recent poll by ABC News/Washington Post found that just 40 percent of Americans approved of Trump, the lowest popularity rating of any incoming president since the 1970s.