The bomber detonated the vehicle – an oil tanker laden with explosives, security and hospital officials said, speaking on condition of anonymity under regulations.
Three policemen were among the dead while the rest were civilians, and a number of police were also wounded, the officials said.
No one immediately claimed responsibility for the attack, but the Islamic State of Iraq and the Levant (ISIL) group has carried out similar attacks in the past.
Iraqi forces are fighting ISIL in western Mosul, where some 2,000 fighters are launching fierce counter-attacks. After launching the operation to retake Mosul in October, Iraqi authorities in January declared they recaptured eastern Mosul, which is separated from the city’s western neighbourhoods by the Tigris River.
Iraqi special forces and police fought ISIL to edge closer to the al-Nuri mosque in western Mosul on Wednesday, tightening their control around the landmark site.
The close-quarters fighting is focused on the Old City surrounding the mosque, where ISIL leader Abu Bakr al-Baghdadi proclaimed a caliphate nearly three years ago across territory controlled by the group in both Iraq and Syria.
Thousands of residents have fled from ISIL-held areas inside Mosul, the fighters’ biggest remaining stronghold in Iraq. But tens of thousands more are still trapped inside homes, caught in the fighting, shelling and air strikes.
Western Mosul is densely populated and has proven to be a much more difficult fight for Iraqi and coalition forces, which have resorted to greater use of artillery and air strikes to clear and hold territory.