Iraqi officials have confirmed the death toll at a Shi'ite shrine near Baghdad has risen to 37, and said 62 people were injured in the triple explosion.
Police said the attack on the Sayyid Mohammed shrine in Balad, 50 miles north of Baghdad, began with mortar fire on Thursday evening.
The third bomber was killed before he detonated his explosives.
So-called Islamic State has claimed responsibility for a triple suicide attack north of Baghdad which killed at least 35 people and wounded 60 others.
The attack happened near a Shi'ite mausoleum about 58 miles north of Baghdad on Thursday evening.
The death toll in a triple suicide attack near a Shi'ite mausoleum north of Baghdad has risen to 35, Iraqi security sources have said.
The number of people wounded in the attack on Thursday evening is now understood to be 60, up from an initial estimate of 52.
An attack by 'multiple' suicide bombers and gunmen on a Shiite shrine north of Baghdad has killed 26 and wounded 52 others, Iraqi officials have said.
The attack began late on Thursday night when a suicide bomber targeted policemen guarding the entrance to the Sayyid Mohammed shine in Balad, 50 miles north of the capital Baghdad.
A second bomber entered the shrine with nine gunmen targeting security forces as well as families gathering to celebrate Eid al-Fitr, the holiday marking the end of the holy month of Ramadan.
Police officials said a third bomber was killed.
No group has yet claimed responsibility for the attack.
It comes less than a week after an Islamic State-claimed bombing in Baghdad killed at least 186 people.
Foreign Secretary Philip Hammond has said that it was a mistake to remove members of Saddam Hussein's government from positions of power following the Iraq War.
Many Ba'athist military officers who were in positions of responsibility under Hussein are now in senior positions within the fighting force of so-called Islamic State, Mr Hammond told the House of Commons Foreign Affairs Committee.
Maybe it was too great an ambition to try to simply dismantle a quite sophisticated country with a long-established civilisation, traditions and cultures of its own and recreate a sort of mid-Atlantic construct of what governance should look like, often going against the grain of local culture and local tradition.
As a result of the aftermath of Iraq, the reconstructing of Syria following its current civil war needed to take place with "an appropriate degree of humility", the MP for Runnymede and Weybridge said.
I think nobody really thinks that in one bound we should turn Syria into a European-style democracy overnight. That's not a realistic or perhaps even a desirable outcome.
Mr Hammond also resisted pressure to declare that military action in Iraq had been a mistake, instead saying that lessons could be learned.
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The United States could have completed the invasion of Iraq without the help of the UK, a former US Army colonel has said.
Colonel Peter Mansoor, executive officer to General David Petraeus who led the 2007 American military "surge" in Iraq made the comments while speaking to Good Morning Britain.
He added: "More importantly, it might have given the Bush administration some pause", and added that the "special relationship" between the US and the UK was not about "linking arms".
He called the Iraq War "one of the largest, strategic mistakes in American history", saying he "applauded" the British government for launching the inquiry.
The former UK ambassador to the UN in 2003 has said that he believed Tony Blair felt "pushed" into going to war by the Americans.
I felt that at the time, the British felt it at the time, I think the prime minister felt it at the time, that the Americans pushed us into going into military action too early.
Speaking to the BBC Sir Jeremy added that the former prime minister had wanted a UN resolution backing military intervention in Iraq, but that senior US officials thought it was a "waste of time".
The US State Department has said it will not respond to the Chilcot report's findings, as its focus is on tackling the issues present in the Middle East today.
We are not interested in re-litigating the decisions that lead to the Iraq War in 2003 ... we are not going to go through it [the report], we are not going to examine it, we are not going to try to make an analysis of it or make judgement of the findings one way or another. Our focus is on the challenges we have in Iraq and Syria right now.
I believe that UK officials are taking it seriously and I am going to let them speak to it ... but that's where our focus is right now, not on doing the forensics on decisions that were made 13 years ago.
The long-awaited publication of the Chilcot report has raised many questions - we take a look at some of the key issues.Read the full story ›