An Islamic education centre has been vandalised for the second time in as many months.
Copies of the Koran were torn up at Bahr Academy in Newcastle and the building extensively damaged during a break-in at about 21:00 GMT on Monday.
In January, racist graffiti was daubed on the walls.
Police said both attacks were being treated as hate crimes. Six teenagers, aged between 14 and 18, have been arrested over the latest attack.
Officers were called to the school on Benwell Lane by a neighbour who noticed suspicious activity.
Flammable liquid had been poured on the floor and windows broken.
'Completely unacceptable behaviour'
A Northumbria Police spokesman said: "This is a very distressing incident for members of the Bahr Academy, particularly as it is the second break-in this year.
"Although there is not the same racist graffiti as we saw in the first incident, we are treating this as a hate crime.
"We are aware of the impact incidents of this nature can have on the community and I want to be clear that this type of behaviour is completely unacceptable.
"Our officers have visited the Bahr Academy again today and are working with them to put further measures in place to try and prevent anything like this happening again."
After the January attack, the centre's trustees said they wanted those involved to come to get to know its members, as talking could prevent further attacks.
No-one has been arrested in connection with the first incident.