Iraq's top Shia Muslim cleric on Friday condemned deadly violence that killed protesters at sit-ins this week in the southern holy city of Najaf and said a new government must have the trust and support of the people.

Grand Ayatollah Ali al-Sistani also called on security forces to protect anti-government demonstrators from any further attacks. His remarks were delivered by a representative during his weekly Friday sermon in the holy city of Kerbala.

"It is the security forces that must take responsibility to keep the peace, protect the protest squares and peaceful demonstrators and identify attackers and rabble rousers," he said.

At least eight people were killed on Wednesday when followers of populist cleric Moqtada al-Sadr stormed an anti-government protest camp in Najaf.

Sadr last week instructed his followers to leave some protest sites where they had supported demonstrators after Sadr and Iran-aligned political blocs reached a deal to name new Prime Minister Mohammed Tawfiq Allawi - a choice protesters reject.