Eight people were killed and 17 were injured Wednesday when an improvised explosive device detonated followed by a suicide bomber's explosion, according to police and medical officials.
The attacks targeted people leaving al-Mustafa Shiite mosque after night-time prayers in al-Furat neighborhood in western Baghdad, according to the sources
More than 16 suspects have been arrested by security police, sources told CNN.
Al-Furat, a predominantly Shiite neighborhood, is just two miles from Baghdad International Airport.
During a televised address earlier Wednesday Iraqi Prime Minister Nuri al-Maliki declared an amnesty for all Sunni tribesmen who fought against the government, with the exception of those involved in the killing of Iraqi forces.
Al-Maliki also said he hoped that members of Iraq's parliament would be able to choose a president and prime minister in their next session.
After much anticipation over how it would address the country's turmoil, Iraq's new parliament on Tuesday postponed its first session until next week, citing a lack of a quorum.
The political uncertainty comes as Iraqi forces battle Sunni extremist militants from the Islamic State in Iraq and Syria, or ISIS.
"We are going to postpone because of an urgent matter," the speaker of the parliament said Tuesday. He did not say what the urgent matter was, and it was not immediately clear what happened.
The newly elected parliament convened with 255 out of 328 elected officials attending, which was enough for a legal quorum, the speaker said. But when 90 failed to return after a morning break, there were not enough members to continue.
Many had expected al-Maliki to call for the formation of a new government Tuesday,
Al-Maliki and his Shiite-dominated government have been under pressure from Western and Arab diplomats to be more inclusive of members of Iraq's Sunni minority, who say they have been marginalized and cut out of the political process by the government.
When ISIS fighters swept into northern Iraq, seizing the city of Mosul, reports emerged of some Sunnis either joining the militants or doing nothing to fight them.
Under Iraq's constitution, the parliament has 75 days from when it convenes to pick a prime minister. Lawmakers are under pressure to move faster, but the political body has had trouble moving swiftly in the past. The last time parliament met to pick a prime minister, it took nearly 10 months.
More warplanes arrive
Five more Russian-made Sukhoi Su-25 fighter jets have been delivered to Iraq, the Ministry of Defense said in a statement on Tuesday.
The delivery brought to 10 the number of war planes Russia has delivered so far and the ministry said it is expecting a total of 25 under a contract agreed to by Moscow and Baghdad.
The announcement follows a comment by al-Maliki that militant advances might have been avoided if Iraq had proper air power in the form of fighter jets that Iraq has been trying to get from the United States.
"I'll be frank and say that we were deluded when we signed the contract" with the United States, al-Maliki told the BBC in the interview last week, which was released Friday.
Iraq has now turned to Russia and Belarus to buy fighter jets, he said. "God willing, within one week, this force will be effective and will destroy the terrorists' dens," he said.
Kirkuk annexation condemned
In his weekly address, al-Maliki said the priority was to improve the security situation in the country, even as the political process moves forward.
"Security should be the first and foremost on our agendas," he said.
He thanked Iraq's top Shiite cleric, Ayatollah Ali al-Sistani, for his call for volunteers to pick up arms to defend the country against ISIS and said a new government department would handle their mobilization.
Thousands of people, predominantly Shiites, have answered the call, raising concerns among Sunnis about the rise of Shiite militias.