Flying EDI-FRA-YYZ today, I had to get from Z to B, which required passing through security just before the B20-63ish concourse. A woman and I took the fasttrack lane, which had us merge with a huge queue of people. As we're standing there one of the men in the queue politely told the woman that this lane was for men only. She and I both couldn't believe it, but a couple of men around the guy confirmed it, so she asked the security worker at the conveyor belt/machine if this was true and he said yes, this lane was for men and women had to go to a different queue. The reason I gather is that many of the pax going through security then were bound for Tehran, where of course this is more of a thing.

I haven't ever seen gender-segregated security in a Western airport and still find myself very surprised this happened. Is it common at FRA? And/or at other Western airports when a flight is bound for Iran (or someplace similar)? I have been to Iran and have no trouble at all respecting the gender segregation there, which is very different (in my view) from the segregation in places like Yemen. But it seems frankly crazy that passengers flying from Frankfurt to Toronto would have to go through gender segregated security lines in Frankfurt just because some people from Iran are also going through security at the same time.

My guess is that the airport (or airport security authority in Germany, I don't know what it's called) agreed to offer Tehran-bound flights segregated security, which is fine with me. That's totally different though than the airport requiring non-Tehran-bound-pax to also go through segregated security.

Edit: I'll add that the 'men only' line had only male staff working, 4 or 5 in total, whereas the 'female only' line had both male and female staff working.