The branch was previously targeted in February with graffiti accusing Barclays of “funding the death of 13,000 kids” in another Israel-Gaza protest.
Pictures from the scene show a fire extinguisher with Palestine Action written on the side, alongside red paint sprayed over the bank’s windows and cash machines.
T/Chief Inspector Tom Fisher, of the City of London Police, said: ”At 05:57 this morning, officers were called following reports of red graffiti over the front of a building by Moorgate, which had been criminally damaged.
“Fire extinguishers were used and left at the scene. Investigations are ongoing and no arrests have been made yet.”
The high street bank has been repeatedly targeted by pro-Palestinian activists who accuse it of “complicity in Israel’s attacks on Palestinians” because of its funding of Israeli companies.
A branch in Croydon’s North End was hit last month with similar graffiti including the words “free Palestine”, “baby killers”, while a floor-to-ceiling window was also smashed.
Meanwhile, in January, activists staged occupations of several of the bank’s branches while carrying Palestine flags, including at a branch in Peckham.
Separately, a campaign has been launched to urge the Women’s Super League (WSL) to urgently reconsider its sponsorship deal with Barclays over Israel-Gaza.
Activists staged a protest outside the FA’s offices in Wembley on Monday holding cardboard coffins of those who have lost their lives in the conflict.
They also held banners reading: “Barclays Blood Money” and “Football against genocide”.
The Standard has contacted Barclays for comment.
