An explosion has killed 10 people and injured 15 in Sultanahmet, an historic, tourist district of Istanbul in Turkey, according to the Istanbul governor.                                                                                       Authorities in Turkey have not commented on what caused the explosion which happened near the iconic blue mosque around 10.20 a.m. local time (3.20a.m. ET)
The U.S. Embassy in Turkey tweeted, "Ambassador Bass: Closely following reports of an explosion in #Sultanahmet. Our thoughts are with those affected…"