TARTUS, Syria -- A German ship carrying Iranian arms was stopped by a shipping company after a tip-off about the concealed weapons, which were being ferried to a Syrian port, the German weekly Der Spiegel reported Saturday.

The cargo ship was stopped while carrying the weapons to Syria in contravention of a UN arms embargo, in place against Syrian president Bashar al Assad's regime since the start of a bloody crackdown on protests in the country in March last year.

Iran is also currently under a UN arms embargo, imposed in 2007 amid ongoing concerns over the Islamic Republic's nuclear program, which Tehran claims is peaceful.

The ship -- called the Atlantic Cruiser -- is owned by the German-based company Bockstiegel, but was leased by a Ukrainian firm named White Whale Shipping.

Der Spiegel reported that the weapons were ferried to Djibouti by Iran. They were then loaded aboard the Atlantic Cruiser to be taken to Syria.

On Friday, the ship was stopped in the Mediterranean Sea, about 50 miles (80 kilometers) from the Syrian port of Tartus.

"We had been told that the cargo contained pumps and other machinery of that sort," Der Spiegel quoted Torsten Lueddeke from the freight handlers C.E.G. Bulk Chartering as saying.

The ship's current location was not known, Der Spiegel reported.

The UN says well over 9,000 people have been killed since an uprising against Assad flared 13 months ago.

Click here for more on this story from The Spiegel.