Baghdad ( CNN ) -- The Islamic State of Iraq has claimed responsibility for Thursday 's attacks in that country that killed dozens of people and wounded hundreds more . The umbrella group , which includes al Qaeda in Iraq , issued an audio message that was posted on an al Qaeda-linked website . `` Shiite forces have been conducting campaigns , targeting Sunni people inside their homes day and night , '' the group 's spokesman , Abu Mohammed al-Adnani , said in the message . `` I am calling on Sunni people in Iraq to wake up before it 's too late and put their hands with the jihadis ' hands and stand against the Shiite campaign , '' he said . Al-Adnani added a warning that `` the gates of hell have opened '' and that the Islamic State of Iraq `` will carry out more attacks in the near future by suicide bombers , car bombs and roadside bombs . '' He specifically threatened that the group will track down Shiite judges and investigators . The series of explosions and shootings Thursday killed at least 44 people and wounded more than 200 in Baghdad and elsewhere , police said . While most of the Baghdad attacks targeted majority Shiite neighborhoods , explosions also took place in the majority Sunni provinces of Salaheddin , Diyala , and Mosul . The country has seen more coordinated attacks since U.S. troops withdrew from Iraq at the end of 2011 , the official said . An Iraqi government spokesman declined comment Thursday . The U.S. Embassy in Baghdad said it `` strongly condemns '' the terrorist attacks . `` These heinous acts targeted people going to work and shopping , children going to school and security forces working to protect the citizenry , '' the embassy said , adding the attacks were `` targeted at all the people of Iraq in a desperate effort to undermine Iraqi society and its institutions . '' The United Nations ' Assistance Mission in Iraq also condemned the violence `` in the strongest possible terms . '' `` The continuing violent attacks on Iraqis are totally unacceptable and have to stop , '' said Martin Kobler , special representative of the U.N. secretary-general , in a statement . The attacks `` are meant to hinder the achievement of national unity and stability , '' he said . Iraq 's Sunni , Shiite and Kurdish leaders have squared off in recent months after an arrest warrant was issued for Tariq al-Hashimi , the country 's Sunni vice president . Al-Hashimi is accused of organizing his security detail into a death squad that targeted government and military officials . The warrant was issued shortly after the vice president 's Sunni-backed Iraqiya party said it would boycott Parliament , saying Prime Minister Nuri al-Maliki was cutting it out of the decision-making process . Al-Hashimi last week denied the charges in a televised speech , saying the Iraqi judicial council is under the control and influence of the central government and that the charges are `` politically motivated . '' Iraqi officials expressed concern Thursday that the violence could cast a shadow over Iraq 's hosting the next Arab summit on March 29 . The government said earlier this month that logistical and security arrangements had been agreed upon for the event .
The Islamic State of Iraq claims responsibility for Thursday 's attacks . The group includes al Qaeda in Iraq . The group threatens to track down and target Shiite officials .