A wave of car and roadside bombs hit Baghdad province on Monday evening, killing at least 21 people, while eight security forces members died in other attacks, officials said.
The Baghdad attacks are just the latest coordinated bombings to strike Iraq's capital in recent weeks, as the country witnesses its worst violence since 2008.
This year's surge in violence has raised fears of a relapse into the kind of intense Sunni-Shiite bloodshed that peaked in 2006-2007 and killed tens of thousands of people.
Eight car bombs and two roadside bombs exploded in eight areas in and around Baghdad on Monday, killing at least 21 people and wounding at least 98, officials said.
AFP journalists heard one of the blasts in central Baghdad, followed by emergency vehicle sirens.
The attacks came a day after two bombings in the capital, including a suicide attack against Shiite pilgrims, killed 14 people.
Other attacks targeted Iraqi security forces on Monday, killing eight.
North of Baghdad, two roadside bombs killed four Sahwa anti-Qaeda fighters and wounded five, while another south of the capital killed two Sahwa and wounded six people, among them four Sahwa fighters.
The Sahwa, who joined forces with the United States from late 2006 and helped bring about a sharp reduction in violence in Iraq, are frequently targeted by Sunni militants, who consider them to be traitors.
And south of the city of Fallujah, which is located west of Baghdad, a bombing against an army patrol followed by an attack by gunmen on a checkpoint killed two soldiers and wounded six.
Signup to our newsletter and follow us on Facebook and Twitter!
A guard also caught a woman trying to plant a bomb near a primary school south of Baghdad on Monday.
The woman was trying to place the bomb next to the wall of a school in Madain but was discovered by one of the school's guards, who turned her over to the army with the help of a second guard, said the interior ministry.
It came a day after suicide bombers attacked a primary school and a nearby police station in northern Iraq, killing 18 people, including 10 children.
A total of 36 people were killed in attacks across Iraq on Sunday.
Prime Minister Nuri al-Maliki said on Monday that "what Iraq is being exposed to is a big conspiracy that aims to create strife and sectarianism among the sons of one society."
He also said there was a plan to move Syria's bloody civil war to Iraq.
Diplomats and analysts say the Shiite-led government's failure to address the grievances of Iraq's Sunni Arab minority -- which complains of political exclusion and abuses by security forces -- has driven the surge in unrest.
Violence worsened sharply after security forces stormed a Sunni Arab anti-government protest camp in northern Iraq on April 23, sparking clashes in which dozens died.
The authorities have made some concessions aimed at placating anti-government protesters and Sunnis in general, such as freeing prisoners and raising the salaries of Sunni anti-Al-Qaeda fighters, but underlying issues remain unaddressed.
With the latest violence, more than 200 people have been killed so far this month, and over 4,900 since the beginning of the year, according to AFP figures based on security and medical sources.