The attack came exactly 24 hours after anti-government campaigner Ihab al-Wazni was shot dead, also in the south, sending protest movement supporters onto the streets to demand an end to official impunity.

Hassan was shot several times by an assailant as he arrived home at night near Diwaniyah, in images captured on a surveillance camera, as has been the case in a string of previous such attacks.

He had to be transported to a hospital in the capital that specialises in neurological surgery.

"Ahmed Hassan has been operated on and transferred to intensive care where he will be kept under constant surveillance for a critical period of two weeks," hospital spokesman Mohammed Mouyed said.

On Sunday, Wazni was shot dead in an ambush outside his home in the city of Karbala.

Around 30 activists have died in targeted killings and dozens of others have been abducted since October 2019.

Authorities have consistently failed to publicly identify or charge the perpetrators of these killings.