The yellow pills were packaged in bags bearing the image of a camel and inscribed with "2023". They were captured along with the smuggler in Iraq's northern Nineveh province, the National Security Service said in a statement.

The regional captagon trade has exploded in recent years and the security service emphasised the pills seized had been meant for sale inside Iraq.

Twenty other traffickers were arrested in separate raids across the country, the statement said.

In recent months, Iraq's security services have carried out major drug seizures as the country grapples with the increased trafficking and consumption of captagon and crystal meth -- a more potent synthetic stimulant, traces of which are sometimes found in captagon.

Last month, security forces said they had captured 12 million benzhexol pills, a pharmaceutical drug also taken recreationally.

In March, authorities seized three million captagon tablets at the border with Syria, a major producer of the drug which often travels via Iraq to its final destination in Gulf countries.

Once just a transit country, Iraq "for a few months" has seen increased captagon consumption, security service spokesman Arshad al-Hakim told AFP.

"After the main crystal meth traffickers were arrested, other traffickers started selling captagon," he said.

"Security breaches" along Iraq and Syria's shared 600 kilometre (372 miles) border allow the drug to enter the country, Hakim added.

Joint efforts to secure that porous border were addressed by the countries' foreign ministers during a Baghdad meeting in early June.