Iraq's Shia paramilitaries have deployed fighters to the Syrian border to support security forces after multiple attacks from within Syria.
"After several Iraqi border guard positions came under several attacks by missiles, and backup from security forces was late, the 13th brigade of the Popular Mobilisation Forces (PMF) was deployed and targeted the origins of the launch," Qassem Mesleh, the PMF commander for Iraq's western Anbar province, said in a statement on Friday.
"Operations command and the infantry brigade are now present on the Iraqi-Syrian border in border guard positions to repel any attack or movement by the enemy. This area is not within the PMF's remit but it is our duty to back up all security forces."
The PMF is largely outside of government control, but the Iraqi parliament formally recognised it as a state-affiliated institution when its own forces became depleted in the fight against the Islamic State of Iraq and the Levant group (ISIL, also known as ISIS).
Iraqi Prime Minister Haider al-Abadi declared victory over the armed group earlier this month, marking the end of a three-year war to drive ISIL out of Iraq.
Just six months ago, ISIL still controlled vast expanses of territory, including major cities, on both sides of the Iraq-Syria border. The group's quick advance in Iraq began in 2014 as it captured major cities, including Mosul, Ramadi and Fallujah.
Roughly 63 factions make up the PMF, an umbrella of groups rallied by ethnic and tribal leaders whose fighters are either loyal to religious scholars, Iraqi political leaders, or Iran's Revolutionary Guard Corps.