dybmh
ויהי מבדיל בין מים למים
From today's The Times of Israel ...
UNRWA workers accused of kidnapping woman, taking part in kibbutz massacre - report
From the article: {emphasis-mine}
"In one case the hostage said they were told by the captor’s daughter that he was an UNWRA teacher, fed snacks labeled and distributed by the UN agency, and eventually moved from place to place through UNWRA facilities to avoid detection as Israeli troops closed in."
This suggests UNRWA involvement, complicity, and knowledge of the locations of the hostages beyond the 12 which are accused. To be fair, I'm not sure what can be expected from individual Gazans if they are oppossed to the kidnapping. However, I think, based on this and other details in the article posted, it's reasonable to conclude that there arre many more than 12 UNRWA personnel involved.