Jordan said on Monday pro-Iranian Syrian army units and militias loyal to Tehran are stepping up their attempts to smuggle hundreds of millions of dollars worth of drugs across the Jordanian border to wealthy Gulf markets.
The army said it was bracing for an escalation in confrontations with armed smugglers trying to drop large amounts of drugs along the rugged border terrain with Syria.
"We 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.
Jordan said four smugglers were killed by the army on Sunday in the latest showdown along the border that has left at least 40 infiltrators dead and hundreds injured since the start of the year, mostly nomads employed by Iran-linked militias who hold sway in southern Syria.
Jordan is both a destination and a main transit route to the oil-rich Gulf countries for the Syrian-made cheap amphetamine known as captagon.
War-torn Syria has become the region's main production site for a multi-billion-dollar trade also destined for Europe. Syrian President Bashar al-Assad's government denies involvement in drug making and smuggling.
The sharp rise in smuggling attempts has forced Jordan to change army rules of engagement along the border where it has given its military the authority to use overwhelming force.
Jordan's King Abdullah said last week he feared that a Russian withdrawal from southern Syria as a result of the Ukraine war would allow Iran-backed militias to fill the void.
The growing influence of Iranian-backed militias including Lebanon's Hezbollah group in southern Syria in recent years has already alarmed both Jordan and Israel.
Jordanian officials say their concerns about the alarming spike had been raised with Syrian authorities but have not seen any real attempt to clamp-down on the illicit trade.
"Our demands were always that forces do their job but we have not felt so far we have a real partner in protecting the borders," Brigadier General Ahmad Khleifat, the head of border security, told al Glad newspaper.
"The smuggling operations are getting support from elements within the Syrian army and its security agencies and also Hizbollah militias and Iranian militias present in southern Syria."
Jordan said the amounts confiscated in the last five months exceeded 20 million captagon tablets compared to 14 million for the whole of last year.