Tal Afar Mayor Abdul Aal Abbas al-Obedi said a car parked outside a popular downtown restaurant exploded in the early afternoon. As people rushed to the scene to help, a suicide bomber in the crowd detonated his explosives belt, al-Obedi said.
Al-Obedi and local politician Qusai Abbas said 13 people were killed in Tal Afar, a mixed Sunni Arab-Turkomen city about 90 miles (150 kilometers) east of the Syrian border and 260 miles (420 kilometers) northwest of Baghdad.
Abbas said 22 people were wounded, although al-Obedi put the injuries at 15. Such confusion is common in the immediate aftermath of attacks in Iraq.
There was no immediate claim of responsibility for the attack, but car bombs and suicide bombers are hallmarks of al-Qaida.
Tal Afar was a major battleground between U.S. forces and Iraqi insurgents in 2005, and the Americans claimed it as one of their first lasting counterinsurgency victories. It has however seen infrequent but bloody militant attacks in the years since.
"The blasts of today turn our memories backward to the previous years of explosions, and return our minds to the violence and sectarian displacement of the people of Tal Afar then," said Abbas, a member of the Ninevah provincial council that includes representatives for the city.
The town sits strategically between the Syrian border and the Ninevah capital of Mosul, which for years was a hotbed of insurgency during the years Iraq teetered on the edge of civil war. Sunni fighters emboldened by al-Qaida's battle in Iraq traveled from Syria to train and plot attacks in Mosul before heading south toward Baghdad to target the Shiite-led government and pilgrims there.
A September 2005 offensive by U.S. and Iraqi troops chased extremists into the barren countryside. But the insurgency managed to keep a toehold in the city, which was devastated by a March 2007 marketplace attack where truck bombs killed 152 people. Shiites and police then went on a reprisal rampage, killing 70 Sunnis and prolonging the cycle of violence.
Though al-Qaida's threat has been drastically weakened in Mosul over the last five years, it remains potent, and the city continues to be a staging ground for Iraqi fighters and smugglers now heading to Syria to help opposition forces overthrow the regime of Syrian President Bashar Assad, whose religion is an offshoot of Shiism.
Wednesday's attack signals "that Tal Afar is still a hot area, and remains an al-Qaida stronghold as an area used by insurgents crossing the borders from and to Syria," Abbas said.
Al-Qaida frequently targets security forces, as in a Monday attack in the western Iraqi city of Haditha where 25 policemen were killed in a brazen pre-dawn assault by insurgents dressed as government troops. Al-Obedi said only civilians were killed in the Tal Afar restaurant.
"This cowardly terrorist attack only targeted poor civilians," he said. "There were no police or troops in this popular restaurant."
Also on Wednesday, separate car bombings in Baghdad killed four people and wounded 14 in a Sunni area of the capital, according to police who spoke on condition of anonymity because they were not authorized to release the information.
Violence has dropped considerably since the height of Iraq's insurgency just a few years ago, but deadly attacks still happen almost every day.