Tension mounts in Iraq after arrest of militia leader

Tensions mounted in Iraq's capital on Wednesday after the arrest of a militia commander on terrorism charges, prompting a dangerous showdown by the detainee's paramilitary supporters and the Iraqi government.

Stepped up security measures were implemented in Baghdad on Wednesday evening and soldiers were seen patrolling various parts of the city.

The confrontation began after Iraqi security forces arrested at dawn militia leader Qassim Mahmoud Musleh based on a judicial investigation and arrest warrant on terrorism charges, Iraq's military said in a statement.

The statement said he was being questioned by a joint investigative committee.

Musleh is the head of the Popular Mobilization Forces in Anbar province.

The PMF is a state-sanctioned group comprised of an array of militias formed to defeat the Islamic State group in 2014.

Among the most powerful members of the group are Iran-backed Shiite militia groups.

Shortly after the arrest, forces affiliated with the PMF, which maintains offices inside the heavily fortified Green Zone, were deployed surrounding Prime Minister Mustafa al-Kadhimi's headquarters.

Tensions reached fever pitch when Iraqi security forces and the elite Counter-Terrorism Service were deployed to protect the government and diplomatic missions, sparking fears of violence.

Some armed PMF factions gathered around the Green Zone's entrance gates.

The prime minister described the show of force as "a serious violation of the Iraqi constitution and the laws in force," adding in a statement "we have directed an immediate investigation into these movements."