ATHENS, Greece (AP) — Greek authorities said Saturday they seized more than three tons of the prescription nerve pain drug pregabalin and impounded a yacht registered in the United Kingdom.

The operation took place Thursday night at the port of Lavrio, 70 kilometers (43 miles) southeast of Athens, the coast guard said.

On the yacht, the coast guard found 3.75 million capsules of Nervigesic, a brand name used by Indian pharmaceuticals firm HAB Pharma for pregabalin. The capsules were packaged in 500 cardboard boxes weighing nearly 3.15 tons, the statement said.

Pregabalin is used to treat nerve pain caused by a variety of conditions, such as diabetes and shingles, and also to treat a type of seizure called partial seizure because it has its origin at a single location in the brain.

The raid was ordered based on information from Greece’s “National Intelligence Agency about the activity of networks of Egyptian nationals in Greek territory,” the statement said.

The yacht and its contents remain at the Lavrio port while local authorities conduct an investigation, the coast guard said.