By Paulo Prada
CARACAS (Reuters) - Venezuelan authorities have arrested the American captain of a U.S.-flagged cargo ship after finding three rifles on board, a U.S. Embassy official said.
The other 14 crew members, also Americans, were initially confined to the ship and their movements have since been restricted by Venezuelan authorities, the official added.
The detention followed last month's arrest of another U.S. citizen, who was accused of entering illegally from neighboring Colombia and denounced as a possible "mercenary" by President Hugo Chavez.
Chavez, a socialist seeking re-election next month, is a ferocious critic of Washington, and his nearly 14-year rule has been characterized by frequent bilateral spats and incidents.
The U.S. Embassy official in Caracas said the "Ocean Atlas" had been in Maracaibo port, in west Venezuela, since last week, with the captain detained "a few days ago."
"It's an evolving situation," he added, saying it was unclear if charges were being pressed against the captain or crew.
The official said the embassy was probing whether the detention was related to customs issues with the weapons or if Venezuelan officials were considering more serious charges, such as arms trafficking.
The official did not provide the captain's name.
Officials at Venezuela's Interior and Ports ministries did not respond to calls and email inquiries about the matter.
A spokeswoman for Intermarine LLC, the New Orleans-based company that operates the vessel, also did not provide details.
The embassy official said the rifles were listed on the ship's manifest, but it was unclear whether their presence violated any local law.
Weapons are common on commercial ships and are often deemed necessary as possible defense against pirates or other threats.
A spokesman for the U.S.-based Seafarers International Union, which represents "about half" the ship's crew, said union officials were in touch with the vessel and Intermarine about the detentions.
"We have been and continue to work feverishly to help resolve the situation and ensure the safety of all the mariners," the spokesman said.
The Ocean Atlas, according to Intermarine's website, is a heavy-lift, multipurpose cargo vessel built in 2000 with a length of about 400 feet.
(Additional reporting by Eyanir Chinea.; Editing by Andrew Cawthorne and Peter Cooney)