Faraj al-Haidari, the head of Iraq's Independent High Electoral Commission overseeing the process, said an appeals period to consider challenges to the results would end on March 9 and the new councils would be seated on March 24.
The current council is composed of 20 Shia, 14 Sunnis and seven Kurds.
Saja Qadouri, a member of the current provincial council in Diyala, said organisers wanted to hold the protests on February 12, but decided to delay them until they could get official approval.
Qadouri said a large number of Shia voters could not find their names on eligible voter lists at the polling centres while displaced people who had been driven from their homes through violence in the province had been unable to cast ballots.
|Iraqi forces considered the vote a success as it took place without major violence [AFP]
The electoral commission said ballots in more than 30 polling stations nationwide were nullified because of fraud, but that was not enough to declare the election a failure.
Al-Haidari said violations were scattered and all complaints would be decided by the appeals panel.
"We never expected to make everybody happy and we knew that losers would start to launch accusations against the electoral commission," he said.
"Yet we are confident that our employees have done their jobs in a correct and honest way."
Members of Sunni groups known as the Awakening Councils in Anbar province had taken to the streets alleging fraud in the immediate aftermath of the January 31 vote.
But demonstrations quietened after results were published showing some Sunni gains.
The provincial councils have no direct sway over national affairs, but carry wide powers over regional matters such as business deals and local security.
The fact that the vote occurred without major violence was considered a success for the Iraqi forces who are trying to prove they can take the lead in providing security as the Americans begin to withdraw their forces.
Diyala holds a mix of Iraq's main sectarian and ethnic groups - Sunni, Shia and Kurds - and has been a flashpoint for sectarian fighting.
Violence has ebbed in the area after a Sunni revolt against al-Qaeda in Iraq and a Shia militia ceasefire, but tensions have been rising between mainly Sunni Arabs and Kurds, particularly in the far north of the province.