A secondary school has been forced to close on Monday after a cyber-attack that has resulted in the IT system being "compromised and inaccessible".

Billericay School in School Road wrote to parents on Friday to the school had fallen victim to a “significant cyber malware attack”, which despite the school taking all precautionary actions has shut down their IT network.

The school is totally closed to students in years seven, eight, nine and 12 except for examinations and revision classes.

Year ten students are already due to be absent due to work placementss.

The school has apologised for the significant strain “this will place upon families” and has called the attack a “critical incident.”

A letter to parents from headteacher Patrick Berry said: “During the half term holiday, the school was unfortunately the subject of a significant cyber malware attack.

“You may have read in the national press that this kind of attack on schools and other public institutions is becoming increasingly common.

“Whilst the school has taken all of the precautionary security measures to deal with any such cyber threat, with industry standard firewalls, firmware and malware security, this attack has resulted in all of the school IT system being compromised and inaccessible by a complex encryption.”

He added: “Whilst our IT support staff are working hard to resolve the issue and have already made significant progress in restoring the required systems, the situation as it stands is significantly affecting our ability to operate the school safely and effectively.

“Whilst I appreciate the additional strain this will place upon families, we must be sure that the school can operate safely and effectively in wake of this significant critical incident.

“I will write to you again next week to share with you an update on this incident and on the Raac mitigation work that is currently being undertaken on the school site.”

It is currently unknown if the data of parents and pupils has been accessed by the attacker or the aim of the attack and the perpetrator.

School will resume as standard on Tuesday June 4.