By Rafael Salido & Euronews

Spain's Audiencia Nacional court has ordered a criminal investigation into the arrival of tens of thousands of migrants in Ceuta in July.

In her ruling, investigating judge María Tardón said there were grounds to believe that "criminal conduct allegedly committed abroad had seriously undermined Spain's territorial integrity, using the mass entry into the country to do so."

The decision comes after the judge ruled that the National Court had jurisdiction to investigate alleged crimes against territorial integrity, negligent homicide, and criminal organisation, in line with the criteria set out by the Public Prosecutor's Office.

Tardón said the migrant flow "constitutes one of the characteristic methods of 'hybrid warfare' or the 'grey zone,' with the aim of altering the life and rights of Spanish citizens" in Ceuta.