The Nigerian Navy on Tuesday said it has seized a ship and arrested its 15 Russian crew members on suspicion of arms smuggling, after they found several guns and about 8,500 rounds of ammunition on the boat.

The vessel was intercepted over the weekend in Lagos, Navy spokesman Commodore Aliyu Kabiru said by telephone.

According to him, the vessel belongs to the Moran Security Group, based in Moscow, and was flying a Dutch flag. There was no immediate comment from Moran.

“The vessel was carrying 8,598 ammunitions and different rifles. Investigations are still ongoing,” he said.

He gave no further details. However, Navy source, who could not be named, said 22 Benelli MR1 rifles and several other automatic weapons were found.

Arms smuggling is a flourishing enterprise in Nigeria, which is battling an Islamist insurgency in the north, organized armed robbery and kidnapping gangs in the south and oil thieves and pirates in the southeast. The country is also sometimes used as a conduit for shipping arms into other parts of West Africa or the world.

In 2010, a consignment of rocket launchers, grenades and other explosive from Iran was seized at Lagos, causing a diplomatic incident between the two countries, and later between Iran and Senegal, which accused Iranian security forces of using the route to supply weapons to its Casamance rebels.