Attackers paid $10,000 to get a bomb-laden truck past checkpoints and next to the Iraqi Finance Ministry in last week's attacks, one of the suspected masterminds said in a confession broadcast Sunday.

Seeking to fend off widespread criticism over security lapses, the Iraqi military released what it said was the confession of a Sunni man it identified as the planner of one of the two suicide truck bombings targeting government buildings in Baghdad.

Iraqi lawmakers and other senior officials have traded blame and called for investigations into how the bombers were able to get the explosives-packed trucks so close to government institutions in the heart of the capital.

Maj. Gen. Qassim al-Moussawi, the chief military spokesman for Baghdad, said the man was a senior member of Saddam Hussein's ousted Baath Party who had confessed to supervising the attack against the Finance Ministry before his lawyer and the chief prosecutor.

Wednesday's twin bombings, which also devastated the Foreign Ministry, have battered Prime Minister Nouri al-Maliki's efforts to portray himself as a champion of security before January's parliamentary elections and the government has been eager to assert control over the investigation, announcing arrests but giving few details.

Chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, said he was extremely concerned by the attacks.

"The key is whether this is an indicator of future sectarian violence. And certainly, many of us believe that one way that this can come unwound is through sectarian violence," he said Sunday on CNN's "State of the Union." "The message is that the Iraqi leadership really has to take control and ensure security in their country."

The 57-year-old suspect, wearing a gray and white striped shirt, identified himself as Wisam Ali Khazim Ibrahim and said he was a Baath Party member and former police officer from the Diyala province city of Muqdadiyah, north of Baghdad.

The attackers paid $10,000 to a facilitator who knew the Iraqi security forces manning the checkpoints on the roads from Muqdadiyah to the Finance Ministry, Ibrahim said. That blast caused part of an overpass to collapse and killed nearly 30 people.

Ibrahim said the operation was ordered a month ago by a Baath Party operative in Syria in a bid "to destabilize the regime."

Al-Moussawi aired only Ibrahim's confession but said more than 10 people comprising the whole network involved in the attacks have been arrested. He did not mention the Foreign Ministry but said other confessions would be shown in coming days.

Public confidence has been badly shaken, dealing a major blow to a government eager to demonstrate that it can take over responsibility for the country's security from American combat troops, who pulled back from urban areas on June 30 with plans for a full withdrawal by the end of 2011.

Surveillance video widely broadcast on Iraqi television stations shows a truck carrying three large red water tanks in which the explosives were hidden approach the gate in front of the Foreign Ministry, which is next to the Green Zone. A refrigerated truck was used in the Finance Ministry attack.

The confession was a boost to claims by al-Maliki and other Shiite politicians that an alliance of Al Qaeda and Saddam loyalists known as Baathists was to blame. The U.S. military said the attacks bore the hallmarks of Al Qaeda in Iraq.

The link to Syria and the Baathists is politically explosive. The question of what to do with Saddam-era officials in the civil service, army and police has been at the heart of the Sunni-Shiite divide since the overthrow of Saddam's Sunni-dominated regime in 2003 and has been a major hurdle to national reconciliation efforts.

Last week's bombings occurred a day after al-Maliki met with Syrian President Bashar Assad and called on Damascus to hand over people suspected of Sunni insurgent links and to stop fighters from crossing the border into northern Iraq.

In all, at least 101 people were killed and hundreds others wounded in the series of midmorning blasts, which coincided with the sixth anniversary of the deadly bombing of U.N. headquarters in Baghdad.

Ibrahim said he had joined the Baath Party in 1973 and traveled to Syria in July 2006 as sectarian violence raged in Baghdad. He returned to Iraq the next year.

"I returned to Iraq in August 2007 in order to revive the Baath organization, which was suffering badly in Muqdadiyah," he said in the televised confession.

Muqdadiyah, an area 60 miles north of the capital that holds a volatile mix of Sunni insurgents and Shiite militiamen, has seen some of the worst bloodshed in recent years.

The Iraqi government has frequently trotted out suspects of bombings and other attacks for the media, often airing confessions on television.