The demonstrations took place in the major European capitals on Saturday, a day after an ongoing war between Russia and Ukraine entered its second year.
The Saturday rally in London was organized by Stop the War Coalition. It was held at Portland Place in the city's central area, from which the participants marched towards Trafalgar Square.
The London rally was attended by Jeremy Corbyn, a former Labour Party leader and a current member of the parliament.
Corbyn called on world leaders to unite their actions in order to bring peace to Ukraine. He added that hatred, poverty, terrorism, and refugees are all fruits of war, warning that a new conflict will be just around the corner if the world leaders do nothing about the war in Ukraine.
The protesters in London also chanted anti-war slogans, while holding banners calling for an end to the West's incessant campaign of pumping weapons into Ukraine.
Kyiv's Western allies have so far provided it with billions of dollars worth of heavy arms. Moscow has repeatedly warned that arming Ukraine will only prolong the war and add to the suffering of its people.
"I don't agree with sending weapons [to Ukraine] because it extends the war," said Dalia Sanchez, an anti-war activist, adding the Western military alliance of NATO and Russia should engage in talks to prevent more escalation and deaths, PressTV reported.
John Clark, another anti-war demonstrator, said NATO's eastward expansion was not right, adding, "I am here today just because I think we need to stop warmongers and we need to reconsider what is happening."
In Paris, hundreds of people demonstrated against the war in Ukraine. According to the police, the rally attracted around 3,000 participants.
Other demonstrations simultaneously took place in other French cities such as Bordeaux, Rennes or Montpellier, as well as in other European capitals such as Berlin and Brussels.
MP/PR