Deepest sympathies for the families of those killed in Bulgaria, and for those being killed in Syria and elsewhere at the same time. It's a time of mourning. Yes, such a precision attack requires good intelligence - so it's feasible that government agents, perhaps of Iran, are behind this attack. Similarly, the precision attack on Assad's closest aides required a much greater level of intelligence - so it's feasible that government agents, perhaps of the USA, are behind that attack. There's a lot coming to a head in the Middle East. Very few seem to understand, or make an attempt to understand its historical backdrop. Now's not a time for blind vengeance. Those who consider themselves 'civilized' need to take the higher road and hold back and formulate a long-term strategy for co-existence.
2 Turkish security personnel killed, 24 wounded by Kurdish suicide bomb in eastern Turkey (Reuters)
from the article: 7 reported killed in terror attack against Israelis in Bulgaria