Iraqi security forces have seized more than a tonne of Captagon tablets smuggled from Syria via Turkey, the interior ministry said on Sunday.

Ministry spokesman General Moqdad Miri said the Narcotics Directorate "seized a truck from Syria, bound for Iraq, via Turkey, transporting 1.1 tonnes" of the powerful synthetic stimulant.

The seizure was one of the largest in Iraq in recent years and consisted of seven million pills, a security official told AFP, speaking on condition of anonymity.

It was also the first such seizure announced since the toppling in December of Syrian president Bashar al-Assad, whose regime was accused of manufacturing the narcotic on an industrial scale.

The drugs were transferred from a Turkish truck to an Iraqi truck near a border crossing between the two countries, according to video footage released by the interior ministry.

General Miri said there had been arrests, but did not elaborate on the number or nationality of those detained.

He said the seizure operation was mounted with the cooperation of security forces in the autonomous region of Kurdistan, which borders Turkey.

It also took place thanks to "very important information" provided by Saudi security forces, Miri added.

Captagon is an illegal amphetamine-like stimulant that became Syria's largest export during the country's civil war that began in 2011.

In recent years, Iraq and its neighbours, in particular the transit countries Jordan and Saudi Arabia -- the largest consumer market in the Middle East -- to boost cooperation in a bid to combat trafficking.

Iraq in 2022 announced it had seized six million pills, and in 2024 the United Nations Office on Drugs and Crime (UNDOC) said the country had experienced a "dramatic increase" in both the trafficking and use of Captagon in the previous five years.

"In 2023 alone, authorities (in Iraq) seized a record-high 24 million Captagon tablets -- the equivalent of over 4.1 tonnes, with an estimated retail value of between $84 million and $144 million," a UNDOC report said.

It said that between 2019 and 2023, about 82 percent of the Captagon seized in the Middle East originated from Syria, followed by Lebanon at 17 percent.