Three 14-year-old boys, another boy aged 15 and two 13-year-old girls were detained at about 20:45 last night.
Police say graffiti and a small fire was found in the school when the emergency services entered the building.
The teens were all arrested in the grounds of the school on suspicion of break and entry.
The two girls and two of the boys were also arrested under the Fire Service Law.
They were questioned and released on Tuesday night.
In a statement, the school said: “Due to the arson attack last night, school is closed to Nursery, Reception and Key Stage 1 today.
“Open to Key Stage 2 from 08:15 until 12. Children to arrive in playground and head straight to church once registered. Please arrange to collect your child from school at 12.
“Church service is going ahead as planned. Please send your child in Full school uniform this morning and this evening.
“We will be fully open tomorrow once we have cleaned up the school.
“Thanks for your understanding and please share this post.”