Police support officers are guarding the Cenotaph in Rochdale after "Free Palestine" was painted across it ahead of Remembrance Sunday.
It follows two incidents at the cenotaph, one on Monday and one today. It is understood the graffiti appeared on Tuesday afternoon.
Two teenagers, who cannot be named for legal reasons, have been charged with intentionally or recklessly causing public nuisance.
Speaking to Sky News, Billy Howarth, from Rochdale, described it as "heartbreaking".
"I've been coming and going for the last two or three days trying to protect it in small ways," he said.
"This is the third attack on it in a week.
"This community is very veteran-led in Rochdale. It's got a lot of veterans - it's disturbing."
Chief Superintendent Nicky Porter, GMP Rochdale district commander, said: "We join communities across Rochdale in being deeply saddened by the incidents at the Cenotaph - the memorial is a particularly poignant reminder of those who have given their lives to our country, particularly at this time year.
"We will not tolerate the criminal disrespect of the town's Memorial Gardens and I hope the action we have already taken in response to these two incidents reassures our communities of that.
"Whilst the area is regularly monitored by CCTV operators and passing patrols, the partnership is working to sustain increased protection at this time. We have Police Community Support Officers at the scene at the moment and we will be looking to put lasting measures in place over the coming hours and days.
"We don't underestimate the impact these events will have on our community of veterans, and I will be personally engaging with them and other community groups throughout this week."
It comes ahead of remembrance ceremonies across the UK this weekend. The Met Police in London have asked pro-Palestine demonstrators not to march.
However, Met Police commissioner Sir Mark Rowley has said the protest will go ahead, adding legally there is "no mechanism to ban a gathering, a static protest" - but that "if there's a march towards the rally... that march in extremis can be banned."
The protest will be "well away" from the monument, organisers have said, instead going from Hyde Park to the US embassy, and that it won't start until after the 11am silence.
On Saturday, the home secretary said anyone vandalising the Cenotaph in central London on Armistice Day "must be put into a jail cell faster than their feet can touch the ground".
Speaking exclusively to Sky News, Suella Braverman said she doesn't want to "undermine" the police process by banning pro-Palestinian protests planned for Armistice Day next weekend, but that behaviour on the marches had been "utterly despicable".
Thousands have protested in recent weeks over Palestinian deaths in the Israel-Hamas war, with 29 arrests during a fourth week of protests last Saturday, when a dispersal order was authorised.
Five people were also arrested at a pro-Palestinian protest at London's King's Cross station on Friday.
No demonstrations are planned in London for Remembrance Sunday, when veterans parade past the Cenotaph and politicians and royals lay wreaths.