The latest protest comes a day after police said three political activists had been killed since the weekend.
There are no reports of any casualties or arrests.
At around 11.00 am (1000 GMT), thousands of protesters gathered near the Gare de Lyon train station for a march towards the Arc de Triomphe.
In the case of the youngest to be killed, a bullet entered the back of 17-year-old J. Snowlin's head and exited through her mouth.
Macron says there must be order, calm and harmony now.
Police said the protestors had tried to break through a cordon several times but had been prevented from doing so, with tear gas used more than once.
The protesters, who linked arms along Whitehall in the heart of London's political district, then delivered a letter to Prime Minister Theresa May saying they were extremely concerned at stalled Brexit negotiations.
Listed by Forbes magazine as one of the world's richest men, Soros is accused by nationalists around the world of sponsoring protests and seeking to push a liberal, multicultural agenda.
The protests were called online by a grassroots group, Committees for the Defence of the Republic (CDRs), founded to help stage last year's banned referendum and now demanding a clean break with the Spanish state.
After a weekend of protests in which right-wing extremists vastly outnumbered counter-protesters, a huge crowd estimated by city authorities as 50,000 people massed at the Chemnitz free concert Monday.
Israeli troops shot dead dozens of Palestinian protesters on the Gaza border on Monday when the high-profile opening of the U.S. embassy to Israel in Jerusalem by the Trump administration raised tension to boiling point after weeks of demonstrations.
Sheikh Ibrahim Zakzaky, head of the Islamic Movement of Nigeria (IMN) has been in government custody since troops clashed with his followers in the northern city of Zaria in December 2015.
The Belarusian opposition is marking the 100th anniversary of the short-lived Belarusian People's Republic of 1918-19 that it sees as the foundation of an independent Belarus.
The marchers demand that soldiers end their backing for the junta, which took power following a May 2014 coup, but also says they did not want another military takeover.
Cambodian Prime Minister Hun Sen, criticised by rights groups for a crackdown on the opposition and media, denounced protesters in Australia as dogs on Thursday for burning his effigy, days after threatening to beat them up.