BAGHDAD - A bicycle bomb exploded near a restaurant in Baghdad Thursday killing two people in a deadly reminder of Iraq's security problems as the death toll rose to at least 101 from a string of blasts the day before that mainly targeted heavily guarded government buildings.

More than 500 people also were wounded when nearly simultaneous truck bombs struck Iraq's Foreign and Finance ministries on Wednesday -- the deadliest day of co-ordinated bombings in more than a year.

The bloodshed dealt a devastating blow to the Iraqi government's efforts to take advantage of security gains to return Baghdad to normal after years of sectarian warfare.

Prime Minister Nouri al-Maliki blamed Sunni insurgents linked to al-Qaida in Iraq and said the attacks were designed to foil plans to reopen streets and remove concrete blast walls from Baghdad's main roads by mid-September.

He said the Iraqi government must reassess security measures -- the first government acknowledgment that the moves may have been premature so soon after U.S. troops left the cities at the end of June.

Al-Maliki convened an emergency meeting late Wednesday with senior security and military officials to discuss "rapid measures to achieve security and stability" in Baghdad and surrounding areas to prevent insurgents from rekindling violence ahead of next year's elections, his office said in a statement.

Maj. Gen. Qassim al-Moussawi, the chief Iraqi military spokesman in Baghdad, said 10 police and army commanders overseeing security, traffic and intelligence services in the targeted areas have been detained on suspicion of negligence.

The deadliest blast on Wednesday targeted the Foreign Ministry, shattering the facade and charring dozens of cars in a parking lot across the street. Police and hospital officials said at least 65 people were killed and 411 wounded in that attack, which reverberated inside the adjacent Green Zone, home to the U.S. Embassy and Iraqi government headquarters.

That attack occurred minutes after a suicide truck bomber took aim at the Finance Ministry complex in northern Baghdad, causing part of a nearby overpass to collapse. At least 28 people were killed and nearly 120 were wounded in that blast, officials said.

The officials, who provided casualty tolls on condition of anonymity because they weren't authorized to release the information, said eight other people were killed and nearly 40 wounded in two other explosions in separate parts of the city.

Attacks resumed on Thursday when the explosives-laden bicycle struck a restaurant shortly before 8 a.m. in downtown Baghdad, killing at least two people and wounding 18, according to al-Moussawi's office.

The uptick in violence has raised fears about the readiness of Iraqi forces to provide security less than two months after U.S. troops withdrew from cities.

The U.S. military has consistently warned that insurgents maintained the capabilities to stage high-profile attacks but the latest blasts indicated a more sustained effort to undermine public trust in the Iraqi government.

U.S. troops withdrew from Iraq's cities June 30 under a security pact that outlines the American withdrawal from the country by the end of 2011. President Barack Obama has ordered all U.S. combat troops out of Iraq by Aug. 31, 2010, leaving up to 50,000 U.S. troops in training and advising roles.