US embassy in Baghdad on high alert over attacks
A statement from the embassy said the decision was due to an increased threat of kidnapping in the city.
"In response, the US Embassy has temporarily restricted movement of its employees outside of the international zone in Baghdad," the embassy said in a statement.
More than 40 members of one Hashed al-Shaabi brigade, Martyrs of Sayyid, were killed on Monday in a series of airstrikes on the Iraq-Syria border.
The Martyrs of Sayyid later claimed in a statement that an alleged US airstrike had hit their position on the border, killing and wounding a large number of their fighters.
"We guarantee the attack will not go unpunished, and we call upon all Islamic resistance units in Iraq to consider an appropriate response," the militia said in a statement.
A spokesperson for the US-led coalition fighting Islamic State in Iraq and Syria denied the coalition's involvement in the deaths.
"Allegations of #Coalition strikes vs. Popular Mobilization Forces near #Iraq - #Syria border are INACCURATE. No Coalition strikes there ATT," Colonel Ryan Dillon tweeted.
Iraqi Prime Minister Haidar al-Abadi said in a statement on Thursday that official working hours were suspended on Thursday in order to help the security situation.
A senior Iraqi officer told The New Arab that a large group of security agents from the Iraqi army, federal police and anti-terrorism group arrived at the embassy on Thursday morning.
This group set up a heavy security perimeter outside the embassy, restricting cars and personnel from reaching near the embassy.