Al Qaeda's Iraq wing has claimed responsibility for a series of bomb attacks in Baghdad on Tuesday in which more than 50 people died.
"What has reached you on Tuesday is just the first drop of rain, and a first phase," the Islamic State of Iraq said in a statement posted on jihadist websites.
The group vowed to take revenge for the Iraqi government's execution of militants convicted of capital offenses, Agence France-Presse reported.
The bombings came hours after Iraq's justice minister pledged that "nothing" would stop the death sentences being applied, AFP said.
At least 56 people were killed and more than 200 wounded when coordinated car, roadside and suicide bombs exploded in and around Baghdad during the Tuesday morning rush hour.
More from GlobalPost: Baghdad attacks signal escalation of Sunni-Shia strife
Most of the explosives were planted in predominantly Shia Muslim areas, part of what analysts say is a growing pattern of attacks on Shias by Sunni extremists resentful of their prominence in Shia Prime Minister Nouri al-Maliki's government.
Maliki has accused those behind the latest bombings of seeking to provoke a sectarian civil war and even claimed that other countries' intelligence services may have been involved, according to the BBC.
The Islamic State of Iraq, which is affiliated with several other Sunni extremist groups as well as Al Qaeda, has carried out dozens of attacks since the beginning of this year alone, Reuters said.
Most recently it claimed responsibility for last week's assault on the Iraqi Justice Ministry, which it claims is "a tool against Sunnis, torturing, terrifying and imprisoning and executing them."