Thousands of Iraqis have braved the scorching summer heat to stage a huge protest in central Baghdad against government corruption.

Men, women and children waved Iraqi flags and chanted through the evening, calling on Prime Minister Haider al-Abadi to dissolve the parliament and sack corrupt government officials.

This is the second Friday of protests in Baghdad and across Iraq, with people initially calling on authorities to address the country's chronic electricity problems as temperatures in the capital soared above 50 degrees Celsius (123 Fahrenheit).

Earlier Friday, Iraq's top Shiite cleric Grand Ayatollah Ali al-Sistani addressed the prime minister in his Friday sermon, calling on al-Abadi to quickly address internal issues in the government "with an iron hand."