Story highlights Baghdad attacks targeted Shiite pilgrims, security forces

Falluja's mayor was shot to death while visiting a sewage plant

Bombings in Falluja, Baghdad and Baquba kill 24 more

Nearly 6,000 people have been killed in attacks across Iraq this year, the U.N. says

The mayor of the Iraqi city of Falluja was shot to death while bombings there, in Baghdad and in another city killed 24 more people Wednesday, police reported.

Adnan al-Jalbawi, Falluja's mayor for the past three years, died in a burst of gunfire while visiting a sewage pumping station, police officials in Anbar province reported. One of the mayor's bodyguards was critically wounded as well, the officials said.

There was no immediate claim of responsibility for the attack, police said. Iraq's Shiite-led government has blamed other recent killings on Sunni extremists loyal to al Qaeda in Iraq, and the Anbar provincial council voted to fire police commander Gen. Hadi Azraiej on Wednesday due to the deteriorating security situation there.

Meanwhile, separate attacks in Baghdad and Baquba, to the north, each killed 10 people, police said. The Baquba bombing targeted pilgrims gathering for the Shiite religious commemoration of Ashura, the holiest day of the Shiite calendar.

Ashura commemorations were frequent targets of jihadist attacks in the years following the U.S.-led invasion in 2003. The 2012 commemoration was the first since the invasion to pass without significant violence.

In Baghdad, Shiite pilgrims and security forces were among the targets of gunfire and more bombs, which left 10 dead and 17 wounded in six separate incidents, police said.

Back in Falluja, bombs destroyed two houses belonging to police officers on the city's east side -- and when onlookers gathered around the homes, which were empty at the time, a second bomb exploded, police said. That blast left four people dead and 14 wounded, women and children among them, they said.

They're the latest victims of the fighting that has persisted in Iraq since the final withdrawal of U.S. troops at the end of 2011. Nearly 6,000 people have been killed so far this year, according to the United Nations.

Falluja, about 60 kilometers (37 miles) west of Baghdad, was a hotbed of resistance to the U.S. occupation of Iraq. American troops fought two major battles to reclaim the city from insurgents in 2004.