Missile defence operators had failed to recalibrate their systems, Tehran says

A report from Iranian investigators on the shooting down in January of a Ukrainian jet has blamed a misaligned air defence system giving wrong information to its operators, who did not seek authorisation to fire before killing all 176 people onboard.

Iranian officials initially blamed the crash of Ukrainian Airlines flight 752 near Tehran on the morning of 8 January on technical problems with the aircraft, but days later admitted their own missiles had mistakenly downed it.

Canada, Ukraine, Britain and others ask for box to be sent to third country for examination

Canada and other countries whose nationals were killed in the Iranian strike on a Ukrainian civilian jet leaving Tehran have stepped up their requests for Iran to hand over the black box to a third party for examination.

Iran’s foreign minister, Mohammad Javad Zarif, has suggested specialist equipment should be sent to Tehran to help the Iranians decrypt the contents of the black box and has given a commitment the box will not be opened except in the presence of all interested parties. But with an impasse looming, western aviation experts have said it is not possible to send the cumbersome equipment to Tehran.