AFP - Muslim clerics slammed Iraqi authorities in their Friday prayer sermons over massive bombings last week, as a top US general warned that he expected insurgents to plan more spectacular attacks.

Among Baghdad's critics was Sheikh Abdul Mahdi al-Karbalai, a representative of Iraq's top Shiite religious leader, who called for a review of security measures in the capital.

Sunday's twin suicide bombings, targeting government offices in central Baghdad, killed 153 people and left more than 500 wounded, the deadliest attacks in the country in more than two years.

"With insurgents having repeated the same bombings, with the same style and in the same secure area, we have to review the security plan that has been implemented in Baghdad," Karbalai said, referring to similar attacks on other ministries in August that killed around 100 people.

"I demand immediate and urgent checks for the reasons that led to the bombings," said the representative of Grand Ayatollah Ali al-Sistani.

Security remains tight in Baghdad, with several roads closed off, and stringent checks at multiple checkpoints across the capital.

More than 60 members of the Iraqi security forces have been arrested in connection with the attacks, and the prime minister and his interior and defence ministers are to face questions in parliament.

Baghdad's governor Salah Abdul Razzaq has called for Interior Minister Jawad al-Bolani and Baghdad Operations Command chief Lieutenant General Abboud Qanbar to be sacked over the attacks, which have been claimed by the Islamic State of Iraq, a group linked to Al-Qaeda.

US Major General John D. Johnson, the deputy commander of US operations in Iraq, warned in an interview with AFP that American and Iraqi security forces expected insurgents to plan more massive attacks like Sunday's.

"I think we can't rule out some of these groups' desires to conduct a large attack because they're able to garner a lot of media attention and it's an attempt on their part to be relevant ... and an attempt to intimidate the people," he said.

Asked whether he expected insurgents to attempt more such bombings, he replied: "I can't speak for what it is that they want to try to do, these are the kinds of things that we expect them to attempt to do."

Johnson added that while he expected the security situation to stabilise by the middle of next year, politically motivated violence aimed at influencing the shape of the next government was a concern.

Karbalai's remarks in the central shrine city of Karbala were echoed by clerics in Baghdad, the southern port city of Basra and the shrine city of Najaf.

In the predominantly Shiite Baghdad district of Sadr City, Imam Muhannad al-Mussawi called on Iraq's army and police to reveal "the facts which are hidden from people's eyes about the bombings."

"We demand that the security forces be cleared up, removing all those who cooperate with the terrorists and the occupiers," Mussawi, who is close to radical anti-US cleric Moqtada al-Sadr, told worshippers.