Mass protests in Baghdad after Iraqi activist killings
Thousands are taking part in a protest at Liberation Square in the capital, according to Al-Araby Al-Jadeed, The New Arab's Arabic-language sister service.
Demonstrators managed to bypass cordons obstructing their route to the square, the outlet reported.
Security forces have closed several roads in the centre of Baghdad.
For days protesters have travelled in their hundreds to Baghdad from governorates in Iraq's south for the demonstrations against the killing of activists - believed to have been carried out by Iran-backed militias.
Over 700 protesters have lost their lives since popular demonstrations began in October 2019, Al-Araby Al-Jadeed reported earlier this month.
Iraqi government investigations have not yielded results so far.
Protesters are demanding accountability for the slayings.
Tuesday's action in Baghdad was called after the assassination of Ihab Al-Wazni, the top protest organiser in Karbala, southern Iraq, earlier this month.
Al-Wazni was shot dead outside his house by assailants riding a motorcycle.
The victim's cousin blamed "Iran's militias" for assassinating Al-Wazni, attributing this to the government and security forces being "silent".
Karbala protesters last week also announced their intention to boycott upcoming Iraqi elections.
Demonstrators told Al-Araby Al-Jadeed on Tuesday that security forces had slowed their progress to Liberation Square.
They added that several arrests had been made in the area.
Security forces had started gathering at the main squares since Tuesday morning with reinforcements subsequently arriving when protests grew
Iraq's security apparatus told media four people were arrested, describing them as armed "infiltrators".
In another statement, they said Iraqi Prime Minister Mustafa Al-Kadhimi instructed them to protect the protesters.
Al-Firdous and Al-Andalus Squares have also seen large gatherings where protesters, both locals and southerners, brought banners criticising authorities for failing on services and the economy.
A Karbala activist, Mohammed Al-Bahrani, informed Al-Araby Al-Jadeed on Tuesday that pre-existing demands on services and corruption would be maintained.