BAGHDAD — Iraqi officials say the death toll in a wave of bombings in Baghdad has climbed to 18 people after a series of blasts hit Thursday morning in Baghdad.

The blasts were the worst violence to hit the country since a political crisis between Iraq's Sunni and Shiite factions erupted this weekend. The political spat, which pits Iraq's Shiite prime minister against the highest-ranking Sunni political leader, has raised fears that the Iraq's sectarian wounds will be reopened.

Iraqi officials said at least seven blasts went off early Thursday morning in neighborhoods around the city. At least four people were killed in one western Baghdad neighborhood when two roadside bombs exploded. Three others died in three separate explosions.

All the information came from police and hospital officials who spoke on condition of anonymity because they were not authorized to speak to the media.

In the southwestern neighborhood of Karrada, where one of the victims was killed, sirens could be heard as ambulances rushed to the scene and a large plume of smoke rose over the explosion site.

While Baghdad and Iraq have gotten much safer over the years, explosions like Thursday's are still commonplace.

The political spat between Prime Minister Nouri al-Maliki and the Sunni Vice President Tariq al-Hashemi has plunged Iraq into the worst political crisis in years and raised fears of renewed sectarian violence.

Al-Maliki's government has accused al-Hashemi of running a hit squad that targeted government officials. He's also pushing for a vote of no-confidence against another Sunni politician, the deputy prime minister Saleh al-Mutlaq.

Many Sunnis fear that this is part of a wider campaign to go after Sunni political figures in general and shore up Shiite control across the country at a critical time when all American troops have left the country.