Videos on Twitter show a crowd taking over a Westfield shopping centre in Shepherd's Bush - despite initial attempts by police to block an entrance.
But the invasion inside the shopping centre appeared short-lived. Journalist Damien Gayle reported the No Vaccine Passports protest was cleared from the shopping area after about 20 minutes by police with batons. He said he did not see anyone get hit or arrested.
Marchers, surrounded by police, then proceeded to the centre's car park.
Meanwhile, hundreds more protesters took over Parliament Square on Saturday.
Many in the crowd claimed the coronavirus pandemic is a hoax while others protested against the idea of vaccine passports.
There were placards that read: “My body, my choice”.
Several people set off smoke bombs and one launched a firework.
News agency PA reporter Tess de la Mare tweeted a photo of a bus with multiple stickers on its windscreen, said to be the work of protesters.
She wrote: "Poor driver trying to peel hundreds of anti-vaxx stickers off his bus after getting caught up in today’s protest."
One anti-lockdown protester, who did not give his name, said he was protesting “because I want to be free and I want you to be free and the government are lying to us”.
Another woman said she was attending the protest because the press “are lying to us”.
By around 1.20pm, the crowd started to disperse and head up Whitehall.
Many of the demonstrators had travelled from other parts of the country.
Those attending the protest in central London include TV presenter Gillian McKeith, who argued against a "medical apartheid" and said lockdowns did not work.
Social media reactions were mixed. While some supported protesters and expressed opposition to lockdowns, others criticised them.
Comedian Bennett Arron mocked protesters, suggesting people do have their freedoms as lockdown lifts. He wrote on Twitter:
Others have branded demonstrators "Covidiots", with the hashtag trending on Twitter.
One user wrote: "#londonprotest they don’t want the vaccine, fine who will they run too when they get sick, they don’t want vaccine passports, fine then you can’t travel or attend certain events, we all have choices, but you can’t have it both ways...#COVIDIOTS #coronavirus."
Separately, hundreds of Kill The Bill protesters also gathered in Russell Square to demonstrate against the Police, Crime, Sentencing and Courts Bill.
Proposals in the new bill putting restrictions on protestsl, including time and noise limits. People who damage memorials could also face a jail term of up to 10 years.
Met Police issued an open letter to those joining the protests on Saturday. in the various large public gatherings expected to take place in London today.
The force “urged people to comply with the restrictions that apply to large gatherings.”
It said people who join a protest, which has not carried out a full risk assessment and which breach coronavirus regulations, face a fine. Organisers could also be breaking the law.