A judge in the United Kingdom ruled Amazon UK guilty of breaking air safety laws after repeated warnings and was ordered to pay am $84,000 fine and a $78,000 prosecution fee.

Last week, a jury found Amazon guilty on four counts of safety rule breaches between November 2013 and May 2015. The jury failed to reach a verdict on six counts and acquitted Amazon on one count.

The conviction was based on dangerous items being found in airmail shipments from Amazon. The items in question were laptops containing lithium batteries and aerosol cans containing flammable gas propellants. The packages containing these items had originally been flagged by Amazon’s own security system and sent through to remote facilities for further review where they were incorrectly labeled as safe.

The Royal Mail—which complained to Amazon—found 782 of Amazon’s packages to contain dangerous goods that cannot be airmailed. Amazon’s defense counsel responded to the findings by explaining that Amazon shipped over 300,000,000 packages during the same period.

Judge Michael Grieve said Amazon was guilty of systemic failure for breaching air shipment rules. He said that Amazon knew the rules, had been warned repeatedly, but had failed to take reasonable care to prevent dangerous goods from being shipped by air.

The prosecution was brought by the UK’s Civil Aviation Authority, after a complaint from Royal Mail. Some offenses took place after Amazon knew it was under investigation.

In each case, the items—two packages containing laptop lithium batteries and two containing aerosols that used flammable gas propellant—had been flagged up by Amazon’s computer systems as possibly dangerous goods, and subject to restricted shipping rules. But in each case further review by Amazon staff in China, Romania, and India led to the items being incorrectly re-designated as non-dangerous.

Royal Mail stopped three of the Amazon packages from entering the airmail system while a fourth was stopped by UPS.

In a statement after the sentencing, Amazon said: “The safety of the public, our customers, employees and partners is an absolute priority. We ship millions of products every week and are confident in the sophisticated technologies and processes we have developed to detect potential shipping hazards. We are constantly working to further improve and will continue to work with the CAA in this area.”

Amazon has a history of run-ins with the U.S. Federal Aviation Administration (FAA) over shipments of hazardous materials.

Last June the FAA levied a $350,000 civil penalty against Amazon.com, Inc. for allegedly violating hazardous materials regulations. Between February 2013 and September 2015, Amazon was found to have violated the Hazardous Materials Regulations 24 other times.