Yellow smoke rises from the rooftop of an old building after Israeli soldiers of the Home Front Command rescue unit with wear protective gear, not seen, detonated it during a drill in Azur, near Tel Aviv, Israel, Tuesday, May 28, 2013. Israel launched a national civil defense drill, which the army said this year will focus on the threat of unconventional weapons at a time of growing regional tensions. (AP Photo/Ariel Schalit) ( Mideast Israel Drill )