The initials of the English Defence League were daubed on the wall of a Muslim community centre burned to the ground in north London.
A week earlier in Grimsby a petrol bomb was thrown into a mosque as police guarded it.
Another arson attack may be part of the same pattern.
Firefighters had to evacuate 128 pupils and staff from a Muslim boarding school, Darul Uloom, in the south London suburb of Chislehurst last Saturday.
Two pupils were treated for smoke inhalation. Four young men have since been arrested over the attack.
Racist gangs want to capitalise on Islamophobia after the recent killing of soldier Lee Rigby in Woolwich.
We must stop them.