Bombings targeting security forces in northern Iraq killed at least 16 people Sunday, authorities said, as the country prepares for a crucial election later this month.

In the deadliest attack, an explosives-laden parked car exploded as a joint Iraqi army and police patrol passed through a busy commercial area in Mosul, killing five civilians and five security personnel, a police officer said. He said the blast wounded 12.

A medical official confirmed the figures. Both officials spoke on condition of anonymity as they were not authorized to release the information.

Mosul is located about 225 miles northwest of Baghdad.

Hours earlier, a suicide car bomber drove his vehicle into a security checkpoint in the northern town of Dibis, killing six people and wounding 15, police chief Col. Bestoon Rasheed said. Civilians were among the victims, but a breakdown of the casualties was not immediately available.

Dibis is located near the city of Kirkuk, 180 miles north of Baghdad.

Violence has escalated in Iraq over the past year, with 2013 seeing the highest death toll since the worst sectarian bloodletting in 2007, according to the United Nations figures.  More than 8,800 people were killed in violence last year.

No one immediately claimed responsibility for the attacks, but suicide bombings and well-coordinated attacks are a hallmark of an Al Qaeda's breakaway branch that operates in Iraq, known as the Islamic State of Iraq and the Levant. Sunni Insurgent groups have escalated attacks across the country since last year in bid to undermine the Shiite-led government.

The attacks happened just weeks before parliamentary elections are scheduled to be held on April 30, the first such vote since U.S. forces left Iraq. There will be no voting in parts of the western Anbar province, where security forces are clashing with Islamic militants and fighters who control the provincial capital, Ramadi, and nearly all of the nearby city of Fallujah.