"I always told Zomi that she was my personal humanitarian hero. I was continuously amazed by her positivity and her ability to stay joyful and warm and caring in spite of all the horrible things she must have constantly seen in her work," said Jessica Olney, an aid worker who became close friends with Frankcom when they met in Thailand almost two years ago.

Olney said she last saw her friend two weeks ago in Amman, Jordan.

"The world's in a really bad place right now, and I think that probably Zomi would want, you know, her friends and colleagues to keep going with the work. And yeah, for me, it makes me want to just dedicate myself even more to, you know, just try to follow in her footsteps," she said.

Israeli Prime Minister Benjamin Netanyahu said on Tuesday an Israeli airstrike had mistakenly killed the seven, and the U.S. and other allies called for explanations amid widespread condemnation.