An alliance of insurgent groups linked to al-Qaeda have claimed responsibility for the suicide bomb attack on the Iraqi parliament yesterday.
In a statement, the Islamic State in Iraq said it had sent a 'knight' into Baghdad's highly-fortified Green Zone.
The claim came as the parliament held a special session to condemn the attack, which killed at least one MP.
Speaker Mahmoud Mashhadani said the session sent a 'clear message to all terrorists' seeking to halt Iraq's political processes.
Mr Mashhadani opened the special session by asking MPs to read verses of the Koran to mourn the death of Mohammed Awdh, a member of the National Front for Iraqi Dialogue, a Sunni party that holds 11 seats in parliament.
Leading Shia politician Hadi al-Aamiry said: 'The martyrdom of Mohammed Awadh gave us lessons, the first of which is unity and to be united together against terrorism.'
Deputy Prime Minister Barham Saleh said: 'This is undeniably a difficult blow, but it should unify us to confront the evil of terrorism and it proves that terrorism is indiscriminate. Sunnis, Shias Kurds and Arabs were maimed in this attack.'
Yesterday's bombing was the worst breach of security in Baghdad's Green Zone that houses parliament, government offices and the US embassy.
Security was stepped up as all vehicles and their drivers were being thoroughly searched, mobile checkpoints set up and several streets blocked off as police raided some houses inside the sprawling compound.
Iraqi officials are investigating how the suicide bomber managed to slip past multiple checkpoints and blow himself up among MPs in the parliament's cafeteria, targeting deputies from across Iraq's deep religious divide.
The attack came during lunchtime. More than 23 people were injured, about half of them MPs.
It is believed the bomber may have previously been an MP's bodyguard.
