Greek authorities said Sunday they had seized a ton of heroin in a warehouse near Athens -- the second such seizure in little more than a week -- and arrested 14 people, most of them members of a tanker crew.

"These coordinated efforts ... led to the largest seizure of heroin on a European level," Shipping Minister Miltiadis Varvitsiotis said.

Reuters reported 987 kilograms of heroin were brought in by the Togo-flagged tanker Noor One. Greek port police in Koropi said the vessel was seized as well.

NDTV said the seizure was Friday.

Officials said the vessel passed by Oman and Pakistan before it was seized off Elefsina.

Police said 10 of those arrested were members of the tanker crew, five of them Turkish nationals. The others included the Greek head of the company that owns the ship although the company was not identified.

More than a ton of heroin was found at two locations in Koropi, about 25 miles from Athens, June 12. Eleven people were arrested in that incident and the Noor One was also believed to have been involved.

The drug was destined for markets around Europe.