A series of bomb attacks swept across Iraq on Tuesday, killing 30 people and wounding some 53 others, amid a wave of escalation of violence in Iraqi cities.

Massive twin car bomb explosions in Iraq's southern central city of Diwaniyah were the latest in a series of high-profile and coordinated bombings that have seemingly shaken Iraqis' confidence in their security forces as the U.S. forces are suppose to completely leave the country by the end of 2011.

The attack occurred in the morning when two booby-trapped cars went off during a shift change of guards at the checkpoint outside the house of Salim Hussein Alwan, the governor of al-Qadsiyah province.

Alwan's house located in the al-Soub al-Sagheer neighborhood in downtown the provincial capital city of Diwaniyah, some 180 km south of Baghdad.

The powerful blasts resulted in the killing of 25 people and the wounding of some 34 others, according to the provincial police reports, which also confirmed that most of the victims were security guards gathering at the site and some other victims were residents inside the neighboring houses.

"Alwan himself and his family members escaped the blasts unharmed," the source said.

Iraqi official television aired footage showing twisted and charred wreckage of several cars and police vehicles scattered at the scene and the surrounding area.

Kareem Zghaiyr, member of the security committee of the provincial council, said that the attack targeted the house of the governor, which is part of provincial government compound, blaming Saddam Hussein's Baath party loyalists and the terrorist group of Qaida for the attack.

"The attack is a significant security breach because there were many checkpoints in the city and across the province and we are investigating how the terrorists could bring the booby-trapped cars to the site," Zghaiyr said.

"I believe that the attack was carried out by the terrorists from al-Qaida organization and the Baath party," he added.

In western Iraq, the Iraqi security forces foiled another massive car bomb attack when they discovered two explosive-laden cars at a side street leading to the government compound in central the city of Ramadi, some 110 km west of Baghdad, a local police told Xinhua on condition of anonymity.

Iraqi explosive experts carried out controlled explosions for the two car bombs without causing casualties, the source said.

Meanwhile, a policeman was injured when a roadside bomb hit his patrol in the town of Garma near the city of Falluajh, some 50 km west of Baghdad, the source added.

Elsewhere, the Iraqi police reported the killing of three people and the wounding of seven others in a bomb explosion outside a popular coffee shop in the town of al-Mussyab, some 50 km south of Baghdad.

Lieutenant Colonel Salman al-Kharji, police chief of the nearby town of Jbala, was among the wounded as he was inside the coffee shop, the police said.

The town of al-Mussyab is part of the once restive area, dubbed Triangle of Death, which is a cluster of towns scattered north of Hilla city, the capital of Babil province, some 100 km south of Baghdad.

In Baghdad, two people were killed and eight wounded in two roadside bomb attacks in the morning in eastern and western the capital, an Interior Ministry source told Xinhua on condition of anonymity.

Separately, two bombs separately went off near two liquor stores in Baghdad's central district of Karrada, damaging the stores and causing no human casualties, the source said.

Also in the capital, five mortar rounds were fired in the afternoon against a joint Iraqi-U.S. military base in Baladiyat district in eastern Baghdad, the source added.

Two of the mortar rounds hit the base and three landed on a nearby garage, wounding three people, he said.

Such wave of violence across the country underscores the challenges that the Iraqi security forces are facing as they struggle to restore stability and normalcy in Iraqi cities several months before the departure of all American forces by the end of 2011.

Tuesday's attacks came one day after the Iraqi leading political parties held their first meeting at the residence of Iraqi President Jalal Talabani in Baghdad to discuss the extension of the U.S. troops' presence in the country beyond the end of 2011 deadline.

"The meeting was successful. We discussed the presence of the U. S. troops in details whether to stay or to leave (the country) and whether we need trainers and the number of them," Talabani said after the meeting.

Talabani said that the Iraqi factions agreed on holding another meeting "soon" to take a unified political decision.

Baghdad and Washington are in debate whether the U.S. troops need to extend the presence of its troops in Iraq beyond the 2011 deadline.

U.S. military forces are to pull out completely from Iraq by the end of 2011, according to the security pact named Status of Forces Agreement (SOFA), which was signed late in 2008 between Baghdad and Washington.