An "anonymous threatening phone call" is reported to have sparked lockdown in a Twickenham school on Thursday.

Details of the incident were shared in an email by Orleans Park School’s headteacher to parents, as seen by MyLondon.

The school allegedly received an untraceable call on May 16 at 2.41pm from a male who claimed he had a gun and intended to visit the school to shoot someone within the next 20 minutes.

The police were quickly contacted and were present at the school to ensure safety.

Students and staff were held until police confirmed it was safe for them to leave.

The headteacher praised the composed response of the school and explained that there would be an extra police presence at school the next day.

Police confirmed their attendance and have announced that it they are treating the event as a hoax.

The headteacher reassured families that the school would open as normal the following day.

In an email sent to parents seen by MyLondon, the school's headteacher gave her account of what happened.

The letter reportedly says: "Dear Families. I want to provide clarity about this afternoon's situation to prevent any speculation.

"At 2:41pm today, we received an anonymous, untraceable phone call to reception from a male, stating he had a firearm and intended to come to the school in 20 minutes to shoot someone.

“We immediately contacted the police, who arrived promptly.

"Students and staff were held until we received authorisation from the police to release them. I have also requested police presence at the start of the school day tomorrow for added security.

"I want to extend my gratitude to all staff and students for their calm and composed response. School will resume as normal tomorrow."

A Met Police spokesperson told MyLondon: "Police were called at about 2.40pm on Thursday, May 16 to a school in Twickenham following concerns regarding a telephone call made to the school.

"Officers attended as a precaution. The matter is being treated as a hoax."