The probe follows Israel’s interception of the flotilla, which the activists said had been ​seeking to deliver humanitarian aid to Gaza ⁠and to challenge Israel’s naval blockade of the ​Palestinian enclave.

The PNAT anti-terrorism prosecutor’s office said it had ​opened the preliminary investigation after a referral from the French foreign ministry on May 28.

The referral was made under Article ​40 of France’s criminal procedure code, which requires ​public officials to report suspected crimes or offences, PNAT said.

The investigation ‌concerns ⁠suspected torture and war crimes, the office said.

Investigations have been entrusted to the OCLCH, France’s central office for combating crimes against humanity and hate crimes, ​PNAT added.

Organisers of ​the flotilla ⁠have said activists were subjected to abuse, with several hospitalised with injuries and ​at least 15 reporting sexual assaults, including ​rape. ⁠The activists have since been released.

Israeli authorities denied the allegations of abuse. Reuters was not able to ⁠verify them ​independently.

Other Western countries, including Canada, ​Germany and Italy, also condemned Israel’s treatment of the activists.