A Hyde Park memorial for the July 7 London bombings was vandalized on Monday morning, ahead of an evening ceremony at the site to commemorate the ninth anniversary of the attacks.

The installation, made up of 52 stainless steel columns, was defaced before dawn with black and red spray-painted stencilings, with slogans including “4Innocent Muslims,” “J7 Truth,” and “Blair Lied Thousands Died.” Photos and videos from London journalist James Banks show the graffiti before it was removed.

According to Police 7/7 memorial in Hyde Park was vandalised last night. More on — James Banks (@Tweetingbanksy)July 7, 2014

“Officers were called by a member of the public shortly before 3.30 this morning and informed of the graffiti, which is being treated as criminal damage,” the Scotland Yard said in a statement, adding that no arrests had been made and an investigation was underway.

"I am shocked and saddened by this incident. It is completely unacceptable and the Metropolitan police is already investigating. I am pleased that the graffiti has been removed so quickly and that today's commemoration ceremony can go ahead as planned,” London Mayor Boris Johnson said about the vandalization.

"The focus today should be, and indeed will be, on honoring the 52 innocent people who died on 7/7, the survivors, and all those affected by the terrible events of nine years ago,” Johnson said.

Opened on the attack’s fourth anniversary in 2009, the structure, that cost almost £1 million ($1.7 million), memorializes the victims who died during multiple bombings on the city’s transportation services on July 7, 2005.

In a planned multi-location suicide attack, two bombs went off before 9AM that morning on trains outside of the Edgware Road and Liverpool Street stations. Another exploded at the same time on a train in transit between King’s Cross and Russell Square. A final bomb was detonated an hour later on a bus in Tavistock Square. Over 700 people were injured during the day's events.

"Today is about the families and the survivors, we are disappointed that it happened, especially for them, but the Royal Parks and Transport for London came out in force and it was cleaned up within a couple of hours," said a spokesperson for the Tim Parry Jonathan Ball Foundation, an organization in charge of Monday’s memorial event, according to the Independent.

Workers quickly cleaned up the graffiti in the morning and the memorial service was held as planned.

A minute of silence was observed and the family members of those that died spoke during the event, with names of those killed read aloud.

"I have no interest in dwelling on it (the vandalism), it is not something I consider to be important. I am here for my sister, I want to celebrate her," 31-year-old Elizabeth Nicholson said during the service, the Belfast Telegraph reported. Nicholson’s sister was killed in the attack on Edgware Road.

According to the same paper, a survivor of the Edgware Road train bombing, Jacqui Putnam, said: "This is not a political memorial, this is not a political event, it is not there to make a political statement. What they did was a childish gesture and it has no place in an event like this."

This isn’t the memorial’s first brush with vandalism, however, the structure was defaced with graffiti just two weeks after its 2009 unveiling.

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