BAGHDAD -- Insurgents unleashed deadly attacks Tuesday against Shiite areas in Baghdad, killing at least 56 people and wounding some 200 more, according to officials. The blasts highlight increasing sectarian tensions in Iraq a decade after the U.S.-led war began.
 

The morning attacks, mostly by car bombs, targeted mainly small restaurants, daily laborers and bus stops in the Iraqi capital within a one-hour period.
 

There was no immediate claim of responsibility, but the attacks bore hallmarks of al Qaeda in Iraq.
The deadly wave of bombings came as the country marked a decade since the U.S.-led war began with the March 19, 2003 invasion. Violence has ebbed but insurgent attacks are still frequent across Iraq.
 

Police officials said the first attack took place near a small restaurant in Baghdad's Mashtal neighborhood. Minutes later, two daily laborers were killed and eight were wounded when a roadside bomb hit the place where they gather every day in an area of New Baghdad.
 

In the neighborhood of Sadr City, a sticky bomb attached to the underside of a minibus killed three commuters and wounded seven people. Another car bomb exploded in a commercial street in the same Shiite area.
 

In the northeastern suburbs of Baghdad, at least four people were killed and eleven others wounded after a car bomb went off near a small restaurant in Hussainiyah neighborhood.
 

In Zafarniyah, two car bombs exploded near a police station, killing five people, including a policeman and wounding 27, said police. In northern Baghdad, a car bomb went off near a bus stop, killing three people and wounding 13.
 

In downtown Baghdad, a car bomb exploded near a restaurant not far away from the well-protected green zone, killing six people, including two soldiers and wounding more than 15. In Shulla, a car bomb exploded near an outdoor market, killing five people and wounding 21.