London (CNN)Vandals have attacked the grave of German political philosopher and revolutionary socialist Karl Marx at Highgate Cemetery in London.
"It looks like someone has had a go at it with a hammer," reads a Twitter post from the cemetery. "It's a Grade I-listed monument; this is no way to treat our heritage."
The cemetery said it will repair the memorial "as far as possible" after the incident.
Ian Dungavell, chief executive of the Friends of Highgate Cemetery Trust, told CNN via telephone that attacks on Marx's memorial are regular but not frequent.
The worst incident was in 1970, he said, when an attempt was made to destroy the memorial using a pipe bomb.
In recent years there have been other attacks involving paint, and on one occasion someone tried to drag Marx's head off the memorial with a rope, said Dungavell.
However, this latest incident is more upsetting because chunks of the white marble panel have been lost and the lead lettering smashed, he said.
"It's such a mindless thing to do," he added.
Marx, who lived from 1818 to 1883, wrote about revolutionary ideas related to class struggles, the flaws of capitalism and human labor.
He published well-known works such as The Communist Manifesto, The Eighteenth Brumaire of Louis Bonaparte and Capital.
"Money is the estranged essence of man's work and his existence, and this alien essence dominates him and he worships it," he wrote in Capital in 1867.
His writings were borrowed, interpreted and adopted by political movements around the world, in countries such as Russia, Cuba and China.
Marx published The Communist Manifesto with Friedrich Engels in 1848, considered the most famous pamphlet in the history of the socialist movement.
In 2018, his hometown of Trier, in southwestern Germany, started selling €0 bills in honor of his 200th birthday on May 5.
"The souvenir plays on Marx's criticism of capitalism," said Norbert Kaethler, managing director of Trier's tourism and marketing office, at the time.