"Border guards foiled an attempt to smuggle a large amount of ammunition and other material from Syria into Jordan, at around 1:30 am. (2230 GMT)," the army said in a statement on its website.
"The guards arrested five people and seized their car," it added without giving any further details.
Jordan says smuggling across the border with Syria has risen by 300 percent in the past year and that hundreds of trafficking attempts have been foiled.
The number of licensed weapons stands at 120,000. But the interior ministry also estimates that there are more than one million unlicensed guns in the nation of seven million people.
The kingdom is home to more than 500,000 Syrian refugees.