Three people were wounded late Wednesday when two mortar shells hit central Baghdad, the National Iraqi News Agency (NINA) reported.
The agency, quoting police sources, said "the first shell hit Street 52, and the second hit the area near Khulani Mosque," both in central Baghdad, DPA reported.
The attack came a day after a series of car bombs and blasts hit at least seven Iraqi cities killing 56 people. An al-Qaeda-linked group on Wednesday claimed responsibility for those attacks, reported the Iraqi website Alsumaria News.
The self-styled militant group, the Islamic State of Iraq, made the claim for Tuesday's attacks in a statement posted on affiliated websites, reported Alsumaria News.
The group said the attacks were aimed at undermining the government's security plan for an Arab League summit scheduled to take place in Baghdad next week.
"The lions of the Sunnis in Baghdad and other provinces of the Islamic State unleashed a new and coordinated wave (of attacks) to strike at the security plan declared by the government of the fools for the meeting of the Arab tyrants," the alleged statement said.
Medical sources said nearly 150 people were wounded, which coincided with the anniversary of the United States-led invasion of Iraq.
The pan-Arab summit on March 29 would be the first to be held in Iraq in more than 20 years. In May, the Arab League postponed a Baghdad conference because of turmoil in several Arab countries.
Iraqi Prime Minister Nuri al-Maliki's government has spent about 450 million dollars on preparations for the summit, including security and infrastructure, according to media reports.