Air force blue ?? pouch.

Pouch has unusual curved form, rather than a normal rectangle. The bag hangs from M1910 wire hooks.







Can anyone please identify the country and use?  Thank you.

Is it a gas mask bag?

I have been wondering about these pouches for a long time. I have one in blue and one in olive drab. They are certainly Dutch, but their exact purpose is unknown. I have seen them being worn by troops in a civil defence exercise in Amsterdam in the late 1960s (from photos that is). They never turn up with ordinary field gear in pictures of Dutch troops in the field.

Again thank you.