UK and US navies test unmanned surveillance ships in Persian Gulf

Saildrone Explorer unmanned sea drones are being tested (Mass Communication Specialist 2nd Class Dawson Roth/US Navy via AP)

The UK and US navies have held a joint drone drill in the Persian Gulf, testing the same unmanned surveillance ships that Iran has twice seized in recent months in the Middle East.

The exercise came as the US Navy separately told commercial shipping companies in the wider Middle East that it would continue using drones in the region and warned against interfering with their operations.