BAGHDAD, Sept 3 (Reuters) - At least 12 people were killed on Thursday in bomb attacks in commercial and residential neighbourhoods across Baghdad, police and medical sources said.

Three people were killed and 10 wounded by a blast at a market in the eastern district of Ameen, the sources said. Two others were killed and seven wounded in Zaafraniya in southern Baghdad, while a blast in the northern area of Suleikh killed two more.

No group immediately claimed responsibility for the attacks, but they took place in Shi'ite areas often targeted by Sunni insurgents from the Islamic State group. The government is struggling to dislodge IS from large swathes of the country's north and west.

Blasts also hit Sunni areas, with three killed and eight wounded at a vegetable market in Tarmiya, about 25 km (15 miles) north of the capital, the sources said. An attack in Baghdad's southern neighbourhood of al-Doura left two others dead and eight wounded.

Separately, an army colonel, Muthana al-Daini, was shot dead on Wednesday evening near Baquba, 65 km (40 miles) east of Baghdad, in a killing his family said was politically motivated.

Daini was the brother of Sunni lawmaker Nahida al-Daini, who has been outspoken in accusing Shi'ite militias of committing atrocities in Diyala province.

"The criminal militias have written on my house that I am wanted due to my statements in defence of the people of Diyala," she told Reuters on Thursday.

The colonel was given a military funeral attended by senior military officials including the army's acting chief of staff.

(Reporting by Saif Hameed; Writing by Stephen Kalin; Editing by Mark Trevelyan) ((stephen.kalin@thomsonreuters.com; +961 81639179; Reuters Messaging: stephen.kalin.thomsonreuters.com@reuters.net))