They flew into Transylvania. I looked away for a minute and they disappeared (actually the page locked down - can't just let it run for free for the peasants - then after refresh they were nowhere).
But two Stratotankers were circling at the SE tip of the Carpathians, I assume they had rendezvous with the F-15s. They were from England, while the fighters appeared in Poland first, south of Krakow.