Iraq on Monday executed Ali Hassan al-Majeed, the Saddam Hussein henchman widely known as "Chemical Ali", for crimes against humanity, government spokesman Ali al-Dabbagh said.
"The death sentence against Ali Hassan al-Majeed has been carried out," Dabbagh said.
News of the hanging came shortly after three suicide car bombs struck downtown Baghdad, killing dozens of people. It was not immediately clear whether the attacks were linked the execution.
Majeed, a cousin of Saddam's who earned his nickname because of his use of poison gas, was executed by hanging, the government said in a statement.
'Chemical Ali' executed (Photo: AFP)
He had received four death sentences, the last about a week ago for an attack on the Iraqi Kurdish town of Halabja in which thousands were killed.
Dabbagh said in a statement that Majeed was not subjected to any abuse during the execution, unlike when Saddam was hanged in December 2006.
Like others in Saddam's inner circle, Majeed owed his rise to family ties to the Iraqi strongman, who came to trust few beyond his Sunni Arab clan based around Tikrit, north of Baghdad.
He played a key role in the purge of the Baath party in 1979, when Saddam, formally installed as head of state, sat on the stage of an auditorium and watched "traitors" being led away to their deaths after their names were called out.
In August 1990, after the invasion of Kuwait, Saddam had appointed him military governor of what was deemed to be Iraq's "19th province" but replaced him three months later for fear his brutal reputation was strengthening the hand of Kuwait's allies.
When a US-led coalition expelled Iraqi forces from the emirate in 1991, Saddam appointed Majeed interior minister to help stamp out the Shi'ite rebellion sweeping southern Iraq.
Reuters and AP contributed to the report