File photo.

The Foreign Ministry has formally called on Israel to ensure the security of Greek citizens detained with other activists intercepted Monday off Cyprus in small boats trying to challenge Israel’s naval blockade of Gaza.

A ministry statement said Greek diplomats are “closely following developments and have made a demarche to Israeli authorities to take all necessary measures for the safety of Greek citizens participating in the Global Sumud Flotilla.”

It was unclear how many Greeks were detained Monday by Israeli forces. The ministry said it was in constant contact with the Greek embassy in Tel Aviv for any necessary consular assistance to the activists.

More than 50 vessels departed the Turkish port of Marmaris last week in the latest fruitless attempt to break the Israeli blockade, with nearly 500 pro-Palestinian activists from 45 countries.