Baghdad - Sixty Iraqi security officials have been arrested following the weekend's twin truck bombings that left at least 155 people dead and hundreds more wounded, the Baghdad's top security officer said Thursday.

"Ten officers and 50 others responsible for security in the neighbourhood ... have been arrested following the explosions in the Iraqi capital of Baghdad on Sunday," General Qassim Atta told reporters.

Sunday's bombings took place in front of the Ministry of Justice in central Baghdad, an area that is impossible to reach without passing through multiple checkpoints.

The question of how two trucks packed with explosives managed to get into the area has puzzled many in the capital.

In a statement, the Baghdad Operations Command said it would arrest and bring to justice security officers at checkpoints where violations occurred in future.

Baghdad Governor Salah Abdel-Raziq, a member of Prime Minister Nuri al-Maliki's Shiite Dawaa Party, alleged that the trucks were from the Water Department of the heavily-Sunni city of Falluja.

Local Falluja official Munthir Hamid denied those allegations as "completely baseless."

"All our trucks are accounted for. We sent none of them to Baghdad. I invite any governmental body to come to verify this,' he said.

The bombings were the most deadly to hit Iraq since 2007. The Islamic State in Iraq, an umbrella Sunni insurgent group including al-Qaeda's Iraqi chapter, claimed responsibility for the attack, and for similar coordinated attacks on August 19 that killed more than 100 people, left more than 1,200 injured, and badly damaged the ministries of finance and foreign affairs. (dpa)