A series of explosions hit Baghdad on Thursday, killing at least seven people in the first wave of attacks on Iraq's capital since a crisis erupted between its Shi'ite-led government and Sunni rivals after the last U.S. troops left, police said.

Two roadside bombs ripped into the central Alawi area, killing at least four people and wounding 14 more, while a car bomb hit the commercial Karrada district, killing one person and wounding six more, police and security officials said.

Two roadside bombs killed two and wounded 10 more in Shula district and near Adhamiya district in the north, while a blast also hit the Shi'ite Shaab district, police and witnesses said.

I saw all the windows were blown out and glass scattered everywhere. The children were scared and crying, said Raghad Khalid, a teacher at a kindergarten near the Karrada blast.

Some parts of the car bomb are inside our building.

Smoke hung over the blast site in Karrada as ambulances rushed in to ferry the wounded to hospital.

Violence in Iraq has ebbed since the height of sectarian slaughter in 2006-2007 when suicide bombers and hit-squads targeted Sunni and Shi'ite communities in attacks that killed thousands and pushed the country to the edge of civil war.

Iraq is still fighting a stubborn insurgency with Sunni Islamists tied to al-Qaeda while Shi'ite militias, who U.S. officials say are backed by Iraq, still stage daily attacks.

Days after the withdrawal of the last U.S. troops nearly nine years after the invasion to oust Saddam Hussein, Iraq's fragile power-sharing government is grappling with its worst crisis since its formation a year ago.

Shi'ite Prime Minister Nuri al-Maliki is seeking the arrest of Sunni Vice President Tareq al-Hashemi on charges he organised assassinations and bombings, and he wants parliament to fire his Sunni deputy Saleh al-Mutlaq.

Maliki's moves against Sunni rivals are stirring sectarian tensions as Sunnis fear he wants to consolidate Shi'ite control. Iraq's Sunni minority feel marginalised since the rise of the Shi'ite majority in Iraq after the 2003 invasion.

(Reporting by Kareem Raheem; Writing by Patrick Markey; Editing by Michael Roddy)