The KDP, the biggest Iraqi Kurdish political party, just had its Mosul headquarters bombed today. At least four killed and 26 wounded. Notice the casualty figure in the report mentions only civilians. It doesn't make reference to military or police killed or wounded. I don't know where this building is located, but it seems likely to me that there would be security forces around, if only the peshmerga (Kurdish militia).
This is a bad development. The Kurds live in the most secure area of Iraq and have consistently been our strongest supporters in the country. Their close proximity to Turkey, with fellow Kurds on the other side of the border, and the protection we provided throughout the 90s with the no fly zone have allowed them to grow into a fairly well developed society by western standards.
It is unknown who is behind the bombing as of yet, but there are many players involved in the Kurdish situation, a situation that is a powderkeg waiting to blow. As has been recognized here before, the Kurds in Iraq, Syria, Iran, and especially Turkey form perhaps the largest nationality without a nation of its own. There is nothing that the four countries that envelope "Kurdistan" want less than they want the Iraqi Kurds to gain independence or significant long term autonomy.
The city of Mosul itself is majority Sunni Muslim with a sizable Kurdish minority. The Sunnis, of course, have lost out big time to both the Shia in the south and the Kurds in the north and so have an obvious axe to grind. Most likely, one of the hydra heads of the Sunni insurgency was behind the attack.
Then there's the PKK, a Kurdish separatist group that clashes with its Iraqi neighbors. The PDK (and its sister party the PUK) have a good thing going in Iraq and don't really want to get involved with the PKK and their movement. The Iraqi Kurds may mouth support for a greater Kurdistan, but they know they are in the best position to actually make something like that come about and bringing in Kurds from other, hostile countries will just make their goal of independance more difficult.
I believe Sunni insurgents are behind the attack, but if they are successful in building on this and sparking a wider conflict with the Kurds, it opens the playing field to the other forces I've mentioned. So I can't say who is really invovled in today's bombing, but its certainly not a positive development. Here's hoping this isn't the start of a long spiral downward to chaos in northern Iraq that has gripped the areas further south along the Tigris.