Shia pilgrims targeted in Iraq

Two mortar rounds and a suicide attack targeting pilgrims heading to a shrine in Baghdad killed six people Tuesday, medical sources and witnesses said.

A hospital official said four people were killed and 12 wounded in a suicide attack near Tahrir Square in central Baghdad shortly after dark.

"I saw a white van speeding on the wrong side of the street," Ali Sahib, a motorist who was being searched by police on the square at the time, said.

"Police opened fire, they hit it and the van crashed into the sidewalk," he said, adding that the van exploded soon after as pilgrims ran away from it.

Two other people were killed and four wounded by two mortar rounds fired on Boub al-Sham, a neighbourhood on the northern outskirts of Baghdad, police and medical sources said.

This is the second suicide attack in less than a week in Baghdad. At least seven people were killed in a car bomb attack against pilgrims on Saturday.

The attack on Tuesday comes as the Iraqi state is failing to answer internal security challenges while fighting IS in the north of the country.

Season of Shia pilgrimage

Every year, millions of Shias from across the world gather at the shrine of Imam al-Kadhim (AD 745-799) located in Baghdad's neighbourhood of Kadhimiya.

According to Shia doctrine, al-Kadhim was the seventh of the 12 imams, the successors of Prophet Muhammad.

Over the past decade, the annual pilgrimage has been the target of extremist groups who have killed thousands of piligrims. 

The Iraqi government has deployed 75,000 members of the security forces to protect the droves of worshippers who have been walking for days towards Kadhimiya in northwestern Baghdad. 

Several major thoroughfares in Baghdad have been blocked to traffic for several days already, bringing the capital to a standstill. 

The government declared a national holiday on Wednesday and Thursday, which will see the climax of the commemoration. 

The marching worshippers and the hundreds of tents along their path where they can rest, eat and drink are considered particularly vulnerable to attacks.