Iraq's capital Baghdad has been hit by a series of blasts for a second day running, killing at least 29 people.
In the first attack, at least 16 police commandos were killed when their patrol was struck in southern Doura district.
Hours later, 10 more policemen died in the same area following two more bomb attacks and ensuing gun battles. Others died in Baghdad and elsewhere.
Meanwhile Iraq's president said the new constitution could still be changed to make it more acceptable to Sunnis.
A final draft of the text was sent to the United Nations on Wednesday, but Jalal Talabani told the BBC's Newshour programme: "There is an open door for Sunni Arabs to come to discuss with us... if they have some reasonable demands we will accept it."
He also said he did not believe that so many Sunnis would vote against the constitution that it would be invalidated.
Mr Talabani also addressed the UN summit in New York, condemning "terrorism" in Iraq and urging the international community to do more to help rebuild the country.
The BBC's Caroline Hawley in Baghdad says the militants are making good on their threats of more bloodshed following Wednesday's attacks, in which more than 182 people died, making it the deadliest day since the 2003 US-led invasion.
In other incidents:
- The bodies of at least six men shot dead are found by police in various parts of Baghdad
- A Shia cleric is killed and three other people are wounded in a bomb attack near a mosque in the northern city of Mosul
- A policeman is killed in an attack by unidentified gunmen in the town of Baquba, north of Baghdad
- Three Shia pilgrims are killed in a drive-by shooting on their way to the holy city of Karbala
- Two police officers are killed and two wounded in the northern city of Kirkuk
- Three civilians are killed in an attack on a ministry of industry bus in east Baghdad.
A group claiming to be al-Qaeda in Iraq released a statement on a website saying it was acting after US and Iraqi forces attacked insurgents in the northern town of Talafar.
BLOODIEST VIOLENCE IN IRAQ
14 Sept 2005 - 182 dead
Suicide car bomber targets Baghdad labourers in worst of a series of bombs
16 Aug 2005 - 90 dead
Suicide bomber detonates fuel tanker in Musayyib
28 Feb 2005 - 114 dead
Suicide car bomb hits government jobseekers in Hilla
24 June 2004 - 100 dead
Co-ordinated blasts in Mosul and four other cities
2 March 2004 - 140 dead
Suicide bombers attack Shia festival-goers in Karbala and Baghdad
1 Feb 2004 - 105 dead
Twin attacks on Kurdish parties' offices in Irbil
28 Aug 2003 - 85 dead
Car bomb at Najaf shrine kills Shia cleric Muhammad Baqr Hakim and many others
And in a separate development the leader of al-Qaeda in Iraq, Abu Musab al-Zarqawi, purportedly declared "war against Shias in all of Iraq" in an audio tape released on the internet.
Our correspondent says the country's elite security forces were the primary target of Thursday's violence.
At least 16 members of an elite police unit were killed at 0800 (0400 GMT) when a convoy of police cars was attacked by a suicide car bomber.
The attacker rammed the vehicles as they were passing by a bus station in the Doura district.
The government has responded to this new wave of bombings with an appeal for unity.
Meanwhile the funerals are taking place of many of those killed in Wednesday's deadliest bombing, which targeted construction workers waiting for jobs in the mainly Shia district of Kadhimiya.
The Iraqi health ministry say that the death toll from that blast and others across the city reached 182, with 679 injured.