This article decribes the Japanese attempts to use white phosphorous bombs in air to air combat.
On a flight out of Nadzab on a strike at the Wewak airdrome. we made a run over the target in flights of three and were starting to join up as a Group.
Enemy aircraft were sighted at 12 o'clock high. Our gunners were firing at a plane ((I believe it was a "Val") and something fell off as the plane pulled up. I thought the gunners had knocked a wheel loose but as I watched it falling, it suddenly exploded in a large white burst with at least a dozen tenticles formed by particles dropping from the object. It resembled a giant octupus - a really colorful display.
Later during examinations of the planes, it was noted some of them had holes burnt through the wings. Intelligence concluded it a phosphorus or some other flamable metal bomb. Later I witnessed one more such incident but at a greater distance. Apparently it did not work very well since no casualties were reported and I never saw another one after the second sighting of this air to air bombing.