The blast damaged one of the convoy's vehicles and wounded one of his bodyguards, the source said.
Monday's assassination attack was the fifth this year against Nujaifi, who is the brother of the Iraqi parliament speaker Osama al-Nujaifi.
Also in Mosul, gunmen shot dead an official of the Dawa Islamic party, headed by the Iraqi Prime Minister Nuri al-Maliki, when they opened fire on his car in al-Muthanna district, the source added.
