Police said they were treating the incidents, which occurred between January 6 and January 23 at locations in east and south London, as hate crimes.
Among the seven locations affected were Stratford mosque and Leyton Jamia Masjid, both in east London.
Officers said they were investigating whether the incidents are linked by scanning CCTV amid reports they were being fuelled by an anti-Muslim group online offering £100 for the graffiti attacks.
No arrests have yet been made.
Met Deputy Assistant Commissioner Jon Savell, who is in charge of policing London this weekend, said: “We understand that Muslim communities will be feeling particularly concerned for their safety following this series of shocking hate crimes.
“Hate has no place on our streets, and tackling it is at the centre of our efforts to make Londoners from all backgrounds and communities feel safe.
“Our local officers will continue to work with community leaders and ensure that a thorough investigation is being conducted”.
Stratford Islamic Association, one of the mosques targeted, said it was heartened by the outpouring of support from the local community after the vandalism.
A spokesperson told Sky News: “Those responsible for this act of hate have shamed only themselves.
“This is not an act of faith – it’s an act of cowardice. But they will not intimidate us. We will not live in fear. Together, as a united community, we will stand strong.”
Responding to the Stratford graffiti, Newham mayor Rokhsana Fiaz said she was “deeply troubled and concerned”.
“I understand that this hate crime will have made many members of our valued faith communities anxious and concerned, and that is why I have written to faith leaders in Newham to reassure them that we are taking this incident very seriously,” she said.
“Islamophobia will not be tolerated in our borough and there is no place for hate in Newham.”
The locations targeted with Islamophobic graffiti:
06/01/2025, West Norwood Mosque, SE27
06/01/2025, South Norwood Islamic Community Centre, Croydon, SE25 5JJ
16/01/2025, Thornton Health Islamic Centre, CR7
23/01/2025, Stratford Mosque, Newham, E15
23/01/2025, Leyton JAMAI MASJID, E10
23/01/2025, AL-BIRR Mosque, E10
25/01/2025, Noor Ul Islam Primary School, E10
