In a statement, the Metropolitan Police said: "Police were alerted at around 10:30am hrs on Monday, 9 January, to phone calls made to schools in Roehampton, Ilford and Brent in which bomb threats were made.
"Police officers attended the schools. All three incidents were stood down a short time later. An investigation into the threat will be conducted."
After learning that at least two of the threats affected Jewish schools, the Community Security Trust took the decision, following consultation with the police, to alert all Jewish schools across the UK .
But at no stage was a decision taken to evacuate any school.
At one Jewish primary children were told to adopt security measures used during an emergency situation.
Other schools were placed under temporary lock-down, meaning no one could enter or leave.
In a statement, CST confirmed: “A small number of Jewish schools across the country received bomb threats, as did a small number of non-Jewish schools.
"The Jewish schools followed security procedures, and CST and police immediately responded. All of the sites have been searched, and declared safe and secure. CST thanks school staff, pupils and parents for their calm response to these calls.”
Schools were set to email parents later today to reassure them following the incident.
In a separate incident, several Jewish community centres in the United States received bomb threats.