Several hundred Iraqis took to the streets of Baghdad Friday to vent their anger at the chronic electricity shortages, which they blamed on government corruption.

"Thieves, thieves, thieves," chanted the crowd, mostly middle-class Baghdadis, as they marched before dusk in the centre of the capital.

Iraq's infrastructure was severely damaged during the 2003 US-led invasion that ousted Saddam Hussein and the country has suffered chronic power shortages ever since.

The government has repeatedly promised an end to the crisis, compounded by insurgent attacks since 2003, but shortages have continued and private generators flourished as an alternative.

Power from the national grid is on only a few hours a day in most of the country, making life deeply uncomfortable in the searing summer heat.

The government declared Thursday and Sunday national holidays because the temperature broke the 50-degree Celsius (122 Fahrenheit) mark.

"We are demonstrating against a failed government, a government that has disappointed the hopes of the people," said Nahida Ahmad, a middle-aged woman employed at the ministry of culture.

"We have no services; have they no shame? For years, we have been telling them they are failures, they are thieves, they are corrupt. Have they no shame?"

Many of the demonstrators were civil servants who were not afraid to criticise the government.

"We despair of this government we elected and we are tired of being submitted to those cowards," said Dawood Akram, an engineer at the ministry of water resources.

"Thirteen years with no water, no electricity, no services and with low salaries. The people have had enough," he said.

Other demonstrations have been staged elsewhere in the country over the power shortages. Earlier this month, a young man was killed during a protest near the southern oil hub of Basra.

On Wednesday, Prime Minister Haider al-Abadi ordered state institutions and government officials to save electricity with programmed power cuts.

The demonstrators Friday said corruption and incompetence were at the root of the problem.

"The Hashed al-Shaabi (Popular Mobilisation force) and our brave army are fighting the Dawaesh of murder," said Yunes Hassan, using a reference to members of the Islamic State group.

"We are here to fight the Dawaesh of corruption," said the young computer engineering student.