Jordan says Iran-backed forces in the Syrian army and militias loyal to Tehran are trying to smuggle hundreds of millions of dollars’ worth of drugs across the Jordanian border to Persian Gulf markets.

The Jordanian army said Monday it is preparing for an escalation in confrontations with Iran-backed armed smugglers that have included deadly shootouts and the military downing drug drones since the beginning of the month.

"The Jordanian armed forces are facing a war along the borders, a drugs war and led by organizations supported by foreign parties. These Iranian militias are the most dangerous because they target Jordan's national security," senior army spokesperson Colonel Mustafa Hiari told state-owned Al Mamlaka television.

The skirmishes forced the country to change army rules of engagement along the border where it has given its military the authority to use overwhelming force.

On Sunday, four smugglers were killed in the latest shootout with the military as they tried to cross the rugged Syrian-Jordanian border.

At least 40 infiltrators have been killed and hundreds injured since the start of the year, mostly nomads employed by Iran-linked militias who hold sway in southern Syria.

Domestic consumption in Jordan has risen sharply in the past three years, during which the country has become a regional transit route for addictive pills to the oil-rich Persian Gulf countries, mainly the Syrian-made cheap amphetamine Captagon.

Last week, Jordan’s King Abdullah expressed concern about Iran and its proxies filling a vacuum left by Russians in southern Syria, warning that this could lead to issues along the borders.