The protester embarrassed Otaiba by a question about the children of Yemen, while walking in a street with bodyguard.
"Why are you killing Yemen's children?" He said, in a silent reaction from the UAE ambassador.
The ambassador bodyguard asked the activist to get away, and stop questioning Otaiba.
Th US-Saudi-UAE aggression is accused of killing large numbers of civilians in Yemen, especially children targeted in a school bus.