Hundreds of students will miss lessons today as their school is closed for a deep clean after five teachers tested positive for Covid-19.

An investigation is to take place at Samuel Ward Academy in Haverhill to see how the transmission of the virus happened – and to determine what contact may have taken place between the affected members of staff and all pupils, staff and wider school community.

Anyone who has been in close contact with infected staff has been contacted and asked to self-isolate for 14 days. Further contact tracing will continue and additional pupils and staff may be asked to self-isolate.

Headteacher Andy Hunter said he is “very disappointed” at the disruption.

He said: “The safety of pupils and all those who work at the school is my biggest priority. Obviously this is a huge disappointment after working so hard to get the school back up and running.

“I will be looking closely at the systems we put in place to try to understand how the transmission occurred and to make sure we do everything possible to limit the chances of the same thing happening again.

“I am very disappointed by this disrupted start to the school term. We have taken very extensive precautions. We were delighted that term had started so well last week and were looking forward to the final two year groups starting tomorrow.

“But I have had excellent support from Public Health England, Public Health Suffolk and Suffolk County Council. We are determined to do all we can to stop the further spread of the virus and agree with the precautionary action to close the school tomorrow.”

On the advice of Public Health England, and as a precautionary measure, the school will be closed tomorrow to allow for a deep clean to take place.

The school is hoping to reopen on Tuesday and will notify parents by 5pm on Monday. An Incident Management Team, consisting of representatives from Public Health England, Public Health Suffolk, Children & Young People services at Suffolk County Council and the Unity Schools Partnership, has been formed to deal with this issue.

Stuart Keeble, director of public health at Suffolk County Council, said: “Understandably, this news may worry parents across Suffolk, but it is important to remember that the risk of children contracting COVID-19 is still very small. Evidence suggests that children are more likely to contract Covid-19 at home.

“It is safe for children to be in school and incredibly important for their development and wellbeing. We will continue to offer our support and guidance to ensure that pupils at Samuel Ward are able to get back to their classrooms by Tuesday.”

Tim Coulson, chief executive of Unity Schools Partnership, of which the school is a member, said: “We are working closely with Samuel Ward Academy, Public Health Suffolk, Suffolk County Council and Public Health England.

“While it is regrettable to close the school for a day as a precautionary measure as well as have staff and students isolate, this incident has shown that systems are in place and working to quickly deal with any issues related to Covid-19.”

Dr David Edwards, Consultant in Health Protection, Public Health England East, said: “Our aim is to protect the staff and pupils of the school and prevent any further spread. On this occasion, closure of the school for a day is required to enable contact tracing to be completed so anyone needing to self-isolate is informed before returning to school.”