BAGHDAD: At least five people, including a woman and a child, were killed and nine wounded in a series of attacks in Iraq's restive central province of Diyala on Wednesday, security and hospital officials said.

In the worst attack, four people were killed and seven wounded when insurgents detonated bombs at the homes of three town criers whose job was to awaken people for the Ramazan pre-dawn meal, at around 3:00 am (0000 GMT) in the town of al-Hudaid, west of provincial capital Baquba, according to an Iraqi army colonel in Diyala's security command centre.

“Among the dead were a woman and a child, and two women and a child were among the wounded,” the colonel said, speaking on condition of anonymity. He added that rescue workers were still searching the rubble of the houses, and warned the toll could rise.

Firas al-Dulaimi, a doctor at Baquba general hospital, also said four people had died and seven were injured.

None of the three town criers, who awaken people for early morning meals and dawn prayers before the daily Ramadan fast, were among the casualties, the army colonel said.

In the centre of Baquba, meanwhile, an anti-Qaeda militiaman was gunned down at around 8:00 am (0500 GMT) by insurgents equipped with silenced pistols, according to the colonel.

The militiaman was a member of the Sahwa, made up of Sunni tribes that sided with the US military against al Qaeda from late 2006, helping to turn the tide of Iraq's bloody insurgency.

Also in Baquba, a roadside bomb targeting police Lieutenant Colonel Hamid al-Karkhi left the officer and his driver wounded, the army colonel said.

Meanwhile, in Baghdad, three people were wounded Wednesday morning when a roadside bomb struck against an Iraqi army patrol in Allawi, in the west of the capital, an interior ministry official said.

Wednesday's violence comes after al Qaeda's front group in Iraq threatened a campaign of 100 attacks, starting mid-August, to avenge the death of Osama bin Laden in a US special forces raid in Pakistan nearly four months ago.

Violence is down across Iraq from its peak in 2006 and 2007, but attacks remain common. A total of 259 people were killed in violence in Iraq in July, according to official figures, the second-highest figure in 2011.