19 March 2013
Last updated at 13:10 ET
A series of car bombs mainly targeting Shia areas of the Iraqi capital, Baghdad, has killed nearly 60 people and left more than 150 injured, on the 10th anniversary of the start of US-led campaign that toppled Saddam Hussein.
In a co-ordinated series of attacks, bomb explosions could be heard throughout the morning rush hour on Tuesday. Most of the 10 or so explosions were caused by car bombs, but police said at least one was carried out by a suicide bomber.
Sunni Islamist insurgents linked to al-Qaeda - motivated by the war next door in Syria - are believed by analysts to be regaining ground in Iraq and have stepped up attacks on Shia targets as part of their effort to provoke a wider sectarian confrontation.
No-one has said they carried out the attacks. But suspicion has fallen on the Iraqi branch of al-Qaeda, Islamic State of Iraq, which has launched a number of high-profile bombings this year. Sunni militants have frequently targeted civilians and state officials as they seek to destabilise Nouri al-Maliki's Shia-led government.
Iraq still struggles to maintain security despite the speed with which US and Western troops removed Saddam from power in 2003. Insurgents, sectarian friction and political feuds between Shia, Sunni and Kurdish factions have all added to recent tensions.
Although the current level of violence is still below the numbers of people killed during the height of sectarian violence in 2006, officials warn that al-Qaeda is regrouping in desert areas of Anbar province bordering Syria.
The level of violence has become so great that the country's future as a unified state is hanging in the balance, says the BBC's Jim Muir in Baghdad. Prime Minister Maliki, a Shia, is sharply at odds with Sunni people in the west of the country and Kurds in the north, our correspondent adds.