Maryam Kamalmaz told the Associated Press that eight senior U.S. officials revealed earlier this month that they have specific and highly credible intelligence about the presumed death of her father, Majd.
The activists from the German-based group Last Generation, which has carried out similar protests in the past, were protesting flying, the most polluting form of transportation.
Slovak Prime Minister Robert Fico, 59, was attacked as he greeted supporters following a government meeting Wednesday in the former coal mining town of Handlova.