Gunmen with silenced weapons shot dead a justice ministry worker in the Jamiyah area of Baghdad and killed an agriculture ministry employee in Adil, both in the west of the capital, according to an interior ministry official.
Two soldiers were also shot dead at a checkpoint in Baghdad Jadida in the capital's east, the official said.
A medical official said four people were shot dead in Baghdad on Tuesday.
In the village of Al-Qayara, south of the northern city of Mosul, gunmen killed police Colonel Abdel Monam al-Juburi, while others shot dead one person in eastern Mosul, police First Lieutenant Khaled al-Juburi and Dr Mahmud Zeidan of Mosul General Hospital said.
In Baiji, 200 kilometres (120 miles) north of the capital, a motorcycle bomb killed one policeman and wounded four others, a police lieutenant colonel and a medical source said.
And in Baquba, the capital of Diyala province, a magnetic "sticky bomb" wounded two civilians, a police captain and a medical source said.
At least 69 people, among them 47 security forces members, have been killed in attacks this month, according to an AFP tally based on security and medical officials.
Meanwhile, Adel al-Sumaidai, a Salaheddin provincial council member, told AFP his house in a village called Al-Sadeh was hit by a rocket from a helicopter about 4:00 am (0100 GMT), killing one of his sisters and wounding three others.
He did not specify whether he believed the strike to be accidental or not.
A police lieutenant colonel said Iraqi forces attacked "the hideout of those suspected of killing 15 Iraqi soldiers" in an attack on a military base on July 23, but did not give further details.
While violence has decreased from its peak in 2006 and 2007, attacks remain common across Iraq. There were attacks on 27 of the 31 days in July.
Official figures put the number of people killed in attacks in July at 325, the highest monthly death toll since August 2010.