It would have been better if you had given more information, such as the time period of these photos. Here are some ideas:
1. Send copies to relatives and ask if they can identify anyone. Or post them on your FB page, if you have one, with the same request.
2. If these photos are from the USA, you might give them or copies to your local library when it reopens. Maybe they could do a display asking if anyone can identify the "mystery" people.
3. There are FB groups dedicated to various localities. Another place to post and ask if anyone can identify the people in them. I've seen this done successfully where I live. There may be FB groups related to the places where your foreign photos originated where you could do the same thing.