Residents gather at the site of a bomb attack in Baghdad on Saturday.

Story highlights

Two car bombs exploded as a commemoration for a Shiite imam was winding down

One bomb targeted pilgrims waiting at a bus station to go home

An al Qaeda-linked group claims responsibility for attacks a few days ago

The latest incidents have sparked fears of renewed sectarian violence

Baghdad CNN  — 

Two car bombs targeted Shiite pilgrims Saturday in Baghdad, killing at least 32 people and injuring 68 others, police said.

The bombs detonated as a religious commemoration for Imam Moussa al-Kadhim, one of the 12 revered Shiite imams, was winding down in the northwestern Baghdad neighborhood of Kadhimiya.

One bomb exploded near a bus station in the Shulaa neighborhood, where dozens of pilgrims were waiting for buses home after attending the commemoration. At least 14 people were killed and another 32 were wounded.

A second bomb went off in Sanaa Square killing 18 more people and wounding 36

The car bombs followed a wave of attacks Wednesday that targeted pilgrims headed to Baghdad and killed at least 93 people. Another 100 were injured in what amounted to the the deadliest day of the year in Iraq.

Rising death tolls from bombings make for deadly days in Iraq

The Islamic State of Iraq, an al-Qaeda-linked group, claimed responsibility for Wednesday’s attacks. Its statement called the Shiites “satanic” and vowed to avenge losses suffered by Sunnis in Iraq.

Shiites form a majority in Iraq but for years they were dominated by minority Sunnis empowered by Iraqi ruler Saddam Hussein.

The U.S. invasion of 2003 ousted Hussein and elevated Shiites to positions of power but the war also fanned longtime tensions between the two groups. Many feared hostilities would explode into protracted civil war, though the violence had ebbed by the time the last U.S. soldiers exited Iraq in December 2011.

However, militant Sunnis have not stopped attacking Shiite pilgrims and the scale of this week’s attacks sparked fears of renewed violence on levels of the past.

Iraqi security forces tightened their security measures Saturday in and around Baghdad to protect pilgrims flocking to Imam Moussa al-Kadhim’s shrine. Many began their treks days ago, traveling on foot from the Shiite heartland in southern Iraq and other far-flung places.

Follow the updates on CNN’s Security Clearance blog