Iraqis on Friday mourned a journalist who was gunned down in Baghdad, expressing anger over his death and protesting for reforms a day after the country's anti-corruption chief resigned.

An interior ministry official said on Thursday that journalist Hadi al-Mehdi was shot dead at about 6:30 pm in an apartment on Abu Nawas Street, with a silenced weapon. A medical source at Ibn al-Nafis hospital confirmed his death.

Dozens of Iraqis turned out on Friday to mourn Mehdi, marching from his home in Karrada in central Baghdad with a symbolic coffin covered in an Iraqi flag, towards Tahrir Square.

Protests calling for improved public services, which Mehdi supported, were being held at the square on Friday.

"The martyr was one of the activists in the movement against corruption and the curbing of rights and freedoms, through Facebook and through demonstrations in Tahrir Square," activist Zahir al-Jamaa said.

"He was always stressing the need to reject any violation of the constitution and the law."

"The silenced weapon assassinates everything in my country," the mourners chanted as they marched.

Hattem Hashem, a mourner who had an Iraqi flag draped over his shoulders, said: "The voice of Hadi will not be silenced, despite his assassination with a silenced weapon."

The mourners, who also carried photographs of Mehdi, were prevented by security forces from continuing with the symbolic coffin, and had to leave it behind.

Mehdi was well known for his sharp critiques of government ineptitude and corruption on his show on Demozee radio, and he also wrote commentaries for several websites and was a playwright.

Including the mourners, a total of about 300 people protested at Tahrir Square on Friday.

Some chanted slogans including "Brothers, Sunni and Shiite, we're not going to sell this country" and "We will prevent anyone from taking away our rights."

Protests were held in other Iraqi cities as well.

In the southern port city of Basra, about 500 people protested at the provincial council headquarters, calling on authorities to fight corruption and provide better services.

One banner carried by protesters read: "Where are your promises to reform the regime?"

About 750 people demonstrated in Hilla in central Iraq, chanting slogans including "These jobless people are against the failed regime."

One banner carried by demonstrators asked the government: "What happened to your promises?"

And about 100 people protested in the central shrine city of Najaf, chanting slogans including "No, no to corruption!"

The protests came a day after Iraq's anti-corruption chief resigned, citing political interference in his work.

"Rahim Hassan al-Uqailee, the head of the Integrity Commission, submitted his resignation to Prime Minister Nuri al-Maliki, due to pressure from political parties," an Integrity Commission spokesman told AFP on condition of anonymity on Friday.

Public services in Iraq are poor, especially electricity, with Iraqis receiving just a few hours of government grid power per day.

Anti-corruption watchdog Transparency International rates Iraq as one of the most corrupt countries in the world.