Two senior security officials of Iraq's central province of Salahudin escaped the suicide bomb attacks, Xinhua news agency reported.
In the first attack, a suicide bomber rammed his explosive-laden vehicle into the convoy of police chief Dhamin al-Jubouri near the northern entrance of the city, some 170 km north of Iraq's capital Baghdad, the source said.
Minutes later, another suicide bomber detonated his car near the convoy of Sheikh Jasim al-Jebara, head of the security committee of Salahudin provincial council.
In a separate incident, unidentified gunmen attacked al-Salam security checkpoint, north of Tikrit, killing four soldiers.
No group has yet claimed responsibility for attacks inside and near Tikrit.
The Sunni-dominated province of Salahudin has witnessed a lot of deadly attacks since security forces and allied paramilitary units, known as Hashd Shaabi, retook the province from IS militants who seized a large part of it in June 2014.
