Special briefings were part of the reassurance effort at Britain's Jewish schools following the Paris attacks.
The Community Security Trust wrote to parents of every pupil at Jewish schools on Sunday stressing that "security infrastructure, guarding, procedures and rotas" were in place.
Spencer Lewis, head of Yavneh College in Borehamwood, Hertfordshire, said: "We have reminded all parents of the security measures we have in place and of the importance of ensuring that pupils come straight into school rather than chatting with their friends on the street."
Brigid Smith, headteacher at Liverpool's King David High School said staff and security teams were working to provide "heightened security awareness" for pupils.
At JCoSS in Barnet, head Patrick Moriarty said protection measures remained robust. "The school site is very secure, with guards on active duty at all times at entry points and around the site, assisted by comprehensive CCTV coverage and high-quality infrastructure," he said.
There was a special security briefing run by the Community Security Trust for more than 200 staff members at Europe's biggest Jewish school, JFS, on Tuesday.
In some cases, parents of non-Jewish pupils even contacted CST to air their concerns about children taking part in interfaith trips and visits to Jewish communal sites.
