Relations between neighbours Syria and Iraq have become more complicated since the fall of Assad, who was a close ally of the government in Baghdad.

In Baghdad, Syria's top diplomat Assaad al-Shaibani met his counterpart Fuad Hussein, the official Iraqi News Agency reported.

Iraq is home to a Shiite Muslim majority, and while it is a strategic partner of the United States, it is also a key ally of Iran, once a main backer of Assad's rule.

While Assad's key support came from Russia, Iran and Hezbollah in Lebanon, Iraqi armed groups were also engaged in defending his rule during the 13-year civil war sparked by his crackdown on democracy protests.

The rebels who ended up ousting Assad in December are Sunni Muslim, and interim President Ahmed al-Sharaa, who has sought to present a more moderate image since coming to power, once fought with Al-Qaeda in Iraq against US forces and their allies.

Iraq condemned the massacre of at least 1,383 civilians in coastal Syria earlier this month by security forces, allied groups and jihadists.

The vast majority of the civilians killed were Alawites, members of Assad's sect, itself an offshoot of Shiite Islam.

Iraq said earlier this week that it was investigating an attack on Syrian workers in the country after a newly formed Iraqi group vowed to avenge the mass killing of Alawite civilians.

Supporters of pro-Iran armed groups in Iraq have launched an online campaign against Syrians who they say support the mass killings.

Iraqi forces have in recent days arrested at least 13 Syrians accused of "promoting terrorist groups" and supporting the mass killing in Syria, two interior ministry officials told AFP on condition of anonymity.

Syria's foreign ministry on Wednesday slammed the violence against its citizens, urging Baghdad in a statement to take "necessary measures to ensure the security of Syrians residing in Iraq".