Yes it was a US bomb
More likely supplied by Obama.
"During his time in office, Obama transferred more than $100 billion in over 40 different arms sales to Saudi Arabia, more than any other administration in history."
Yeah, go ahead, attack the source.
https://www.washingtonpost.com/news/checkpoint/wp/2017/01/24/trumps-first-arms-sales-holdovers-from-the-obama-era-are-business-as-usual/?utm_term=.95bcf5e1a5d8