A vandal broke into a school and set fire to a classroom months after the building was devastated by arsonists.

St Philip Howard Catholic School in Barnham had barely recovered from the first attack in December when an intruder tried to start another blaze yesterday.

Detectives believe the fire was started between 12.30am and 1am and burned slowly until staff arrived at 7.30am. A member of staff tackled it before it caused serious damage.

Only last week, students were shown an educational documentary by the fire service teaching about the dangers of starting fires.

A Catholic church spokesman said the attacks were starting to seem "very personal".

The intruder set fire to paper and fled but it failed to ignite fully.

Police and firefighters found a ladder which the arsonist had used to climb into the first-floor library and IT department, near the rooms which were set on fire in December.

Stuart Geary, communications officer for the Diocese of Arundel and Brighton, said it was too early to link the incidents but added: "Clearly when something happens a second time it begins to feel very personal." He said the school might consider fitting security cameras.

December's fire destroyed two classrooms in the main block and caused damage costing thousands of pounds.

The intense heat ruptured the central heating system, pouring gallons of water into the bursar's office.

Home Office forensic experts spent two days sifting the debris for clues. The classrooms were rebuilt and opened nine days later.

A 15-year-old girl was arrested but freed without charge.

Headteacher David Todd said in the school's December newsletter: "Some pupils cried the night the school was on fire. Most who visited the school during the week were upset or angry that someone should have had the temerity to attack their school and their community."

Mr Todd said of the latest fire: "It has had minor impact on the running of the school."

Anyone with information should call Detective Constable Keith Fifield on 0845 6070999 or Crimestoppers on 0800 555111.