The Cenotaph in central London has been boarded up ahead of expected protests this weekend.
The monument was graffitied during last weekend's anti-racism demonstrations, while the nearby Sir Winston Churchill statue in Parliament Square has also been boarded up after it was defaced.
Veterans and soldiers stepped in to clean off the Cenotaph graffiti earlier this week.
Jacob Rees-Mogg has vowed the Government will "earnestly consider" a proposed new law to protect war memorials from being vandalised.
The Commons Leader said attacks on such sites are "contemptible" and he believes no MP would think differently on the issue.
The Black Lives Matter protests were sparked by the death of George Floyd while in police custody in Minneapolis.
While mostly peaceful, there have been clashes between protestors and police in central London and the statue of former slave trader Edward Colston in Bristol was pulled down and dumped in the harbour.
A statue of slave owner Robert Milligan has since been removed from outside the Museum of London.
Meanwhile, the Bournemouth statue of the Scouts founder, Lord Baden-Powell, has been placed under 24-hour security ahead of its removal over concerns it was on a target list compiled by anti-racism activists.
Watch: The Prime Minister says he expects this weekends protests to 'end in deliberate and calculated violence'.
Both the Prime Minister and the Mayor of London have urged people to stay away from upcoming protests.
Boris Johnson said previous demonstrations had been "hijacked by extremists", while Sadiq Khan said he was "extremely concerned" that the further protests could risk spreading COVID-19 and lead to "disorder, vandalism and violence".
"The attacks on police and indiscriminate acts of violence which we have witnessed over the last week are intolerable," the Prime Minister said.
"The only responsible cause of action is to stay away from these protests."
Mr Khan meanwhile said: "Counter-protests are there to provoke violence, and their only goal is to distract and hijack this important issue.
"Staying home and ignoring them is the best response this weekend."
Since the targeting of some monuments, crowds have gathered outside some memorials, claiming to be protecting them from potential vandalism.
Former English Defence League (EDL) leader Tommy Robinson has expressed support for calls by the Democratic Football Lads Alliance for people to travel to the capital to protect monuments.
Black Lives Matter organisers have cancelled a protest in London’s Hyde Park over fears it would be hijacked by far-right groups.
Organisers said the planned protest in the park on Saturday had been cancelled but a similar event on Friday will still go ahead.
According to the National Police Chiefs’ Council, more than 130 people have been arrested as 155,000 people took part in almost 200 demonstrations across the UK.
Cover image: Cenotaph boarded up in central London (Picture: PA).