BAGHDAD — A suicide bomber in a stolen police Humvee passed through a military checkpoint in Iraq before detonating his explosives, part of a series of assaults across the country Saturday that killed seven people, authorities said.

The bomber’s attack happened in Ramadi, the provincial capital of Anbar province, where Iraqi security forces have been battling militants who took control of parts of the town in late December. Police said militants stole the Humvee and painted it with military colors to trick soldiers into letting it by.

The suicide blast wounded 14 people, police said.

Elsewhere on Saturday, a car bomb targeting a street full of shoppers in the capital, Baghdad, killed six people and wounded 14, police said. The blast happened in the capital’s northern Qahirah neighborhood.

In Baqouba, 35 miles northeast of Baghdad, a roadside bomb targeting a military vehicle killed a captain and wounded four soldiers, police said.

Medical officials confirmed the casualty figures for the attacks. All officials spoke on condition of anonymity as they weren’t authorized to release the information.

Widespread chaos nearly tore the country apart following the 2003 U.S.-led invasion that ousted Saddam Hussein. The violence ebbed in 2008 after a series of U.S.-Iraqi military offensives, a Shiite militia cease-fire and a Sunni revolt against al-Qaida in Iraq.

But last year, the country saw the highest death toll since the worst of the country’s sectarian bloodletting, according to the U.N., with 8,868 people killed. The U.N. says more than 1,400 people were killed in January and February alone.

Iraq is to hold its first parliamentary elections since the U.S. troops’ withdrawal in late 2011 in April.