At least 30 schools in the Paris region have this week received threatening messages accompanied by "shocking" footage of beheadings, the education ministry said on Thursday.

The establishments -- mainly secondary schools -- have received "serious threats" containing "justification of and incitement to terrorism," a representative of the education ministry told AFP.

The messages came through the ENT digital platform that serves as a link between teachers, pupils and parents; internal emails; or the Pronote software used by the education ministry.

Investigators were working to "identify the perpetrators", said the ministry, adding that psychological support had been offered to children or adults who had watched the "shocking videos".

According to a police source, at least five high schools in the department of Yvelines, in the west of the Greater Paris region, received bomb threats between Wednesday and Thursday.

Perpetrators "hacked a student's email address" in order to distribute the message and a beheading video, the source said.

In the department of Seine-et-Marne, to the east of the French capital, a secondary school received a message saying that explosives had been hidden throughout the establishment "in the name of Allah", a police source said.

The latest threats follow a flurry of false bomb alerts targeted schools, airport and tourist sites in autumn 2023.

In October, a radicalised Islamist stabbed a former teacher to death in the northern town of Arras.

Prime Minister Gabriel Attal was set to chair a meeting on school security on Thursday