"The first car exploded at 8.20am (0420 GMT) at the entrance to the base used by Iraqi soldiers and border guards" on Saturday in Sinjar, 420km north of Baghdad, said police Colonel Qassem Jaber.
"A few minutes later, the second bomb exploded in the same place," he said.
The attack happened as soldiers and workers entered the base to start work for the day.
Dr Ali Hussein said Sinjar hospital had received five bodies of soldiers and border guards while the wounded had been transferred to other hospitals.
Late on Friday night, an Iraqi youth in Mosul was killed after a bomb targeted Iraqi police.
Idris Ali Muhammad Quba, secretary-general of the Iraqi National Forces and Popular Congress, told Aljazeera that a bomb targeting a police convoy exploded about 10.30pm local time. Several police officers were wounded, he said.
After the blast, police opened fire randomly, killing a youth, Quba said.
Elsewhere, a former member of Kirkuk's city council was shot dead, Reuters reported Iraqi police as saying on Saturday. It was the latest killing of a local official in a city where tensions between Kurds and Arabs run high.
Naif Sabhan al-Jibouri, an Arab tribal leader and former council member, was shot dead outside his home late on Friday, police colonel Adil Zain al-Abdein said.
Al-Jibouri was said to have developed good ties with Kurdish officials on the council, which Kirkuk's deputy mayor suggested might have been a reason for the killing.
Iraqis bid farewell as the coffin of
Naif al-Jibouri is taken away
Over the past two years, more than a dozen local leaders - including Kurds, Arabs and Turkish-speaking Turkmen - have been killed in Kirkuk, a city that draws wealth from huge nearby oil resources and that is claimed by all three groups.
The city is about 250km north of Baghdad.
In the city of Tikrit, north of Baghdad, two membes of the oil pipeline protection force were killed when a suicide bomber blew up his motorcade near the force's patrol.
In the al-Jihad neighbourhood west of Baghdad, a real estate broker Samir Abd al-Razzaq, was shot dead by armed men near a bookshop.
The reasons for the killing remain unknown, however, a police cheif Hamid Hamad and a government employee acompanying Abd al-Razzaq were wounded.
There are fears any explosion of tensions in Kirkuk could provide a spark for a larger ethnic conflict in the country, but so far local animosities have largely been held in check.
Kurds make up about 20% of Iraq's population and live mostly in three northern provinces, where they have their own regional government and enjoy a high degree of autonomy.
Ultimately, Kurdish leaders want Kirkuk assumed into the Kurdish region and made its capital, goals that Arab leaders would staunchly resist.