At least 50 people have been killed in western Baghdad after a suicide bomber detonated explosives packed to a fuel truck.
Another 60 people were injured in the attack on Wednesday in the Iraqi capital's Mansour district according to police.
It was the second deadly explosion in the city in a matter of hours.
Elsewhere in the capital on Wednesday at least 17 people were left dead when a parked car bomb exploded in the busy central district of Karrada.
Meanwhile, a senior US military official has said that while the deployment of US troops has improved security in Iraq to some degree, the country's future is jeopardised by the failure of Iraqi leaders to forge political reconciliation.
Navy Admiral Michael Mullen told a senate hearing that security on the ground in Iraq is "not great, but better".
But Mullen said the US military effort could succeed only if Iraqis struck a compromise to defuse sectarian divisions.
"Barring that, no amount of troops and no amount of time will make much of a difference," he said.
And with that we come to this next item:
Six ministers from Iraq's Sunni bloc have resigned from the Shia-led government of Nuri al-Maliki, the prime minister, following a month-long dispute.
Al-Issawi said: "The [National Accordance] Front announces its withdrawal from the government of Nuri al-Maliki and the deputy prime minister and the ministers will submit their resignation today."
Al-Issawi said: "The front will remain active in the political process hoping that it will be reformed and that sectarian and ethnic divides will disappear."
But he warned that "if the other political parties are not serious, we will rethink the feasibility of our participation in the whole political process."
The announcement comes amid a struggle between the Sunni bloc and the al-Maliki government.
The bloc has accused the government of failing to crack down on Shia militias and of the arbitrary arrest and detention of Sunni citizens, charges that the government has denied.
The withdrawal leaves the resolution of a number of issues - amendments to the Iraqi constitution, laws on oil and gas and de-Baathification - in jeopardy.
Abdel-Hamid said: "Not only the Sunnis have pulled out, the Sadrists - who are the main supporters of prime minister al-Maliki - pulled out last June. So really, there is no unity left."
OK - I think anyone with a brain expects a push to increase the violence level in Baghdad over the next month or so. Not only do we have General Petraeus' report due on the 15th of September but we also have Ramadan starting on the 12th. Traditionally we have seen an increase in violence during Ramadan - no reason to think that will change.
On the issue of the Sunni's withdrawing from the government - This may actually be a good thing. I have said for quite a while that one of the major obstacles to stability in Iraq is al-Maliki. If this forces a no confidence vote and a new election we may end up with a government that is actually interested in suppressing Shia Militia's. It is those militia's that are the major problem in my opinion.
One of the major mistakes in this war was not breaking the militias back in 2003 when we started operations in Sadr City.