Istanbul Bus Bomb Kills 5
Details on CNN here. Twelve were injured and the death toll could rise.
Turkey is in a bad neighborhood, bordering Syria, Iraq and the Caucuses. They have a large Kurdish population pissed off from years of violent repression. A Islamist movement is popular, especially among the newly urban poor, conservative economic refugees from the impoverished countryside. Veterens of jihad in Chechnya and the Balkans, spies from a variety of regional intelligence services, shadowy figures sneaking through insecure borders, it's a bad summer for Turkey.