On Tuesday night, the Cuban foreign ministry said that a North Korean ship, which has been detained in Panama since July 10, was transporting 240 tons of obsolete Soviet-era weapons for repair, along with a 10,000-ton load of sugar, Reuters reported.

The cargo included two anti-aircraft batteries, nine disassembled rockets, and two MiG-21 aircraft, according to the Reuters report.

Authorities in the Central American country of Panama detained the Chong Chon Gang after intelligence reports showed it might be carrying missile systems, in violation of a United Nations sanction on weapons trade against the reclusive Asian nation, according to media reports.

Panama’s President Ricardo Martinelli, according to the Wall Street Journal, said the ship could be carrying drugs and that "containers with sophisticated missiles" were found under containers of sugar.

"The United States strongly supports Panama's decision to inspect the DPRK flagged vessel," State Department deputy spokesman Patrick Ventrell said, according to Reuters. "The United States commends the action that the government of Panama took in this case."

According to the BBC, Martinelli said Panama had stopped the ship for carrying "undeclared military cargo" and that the 35-strong crew had resisted the search and the ship’s captain had tried to kill himself.

The BBC reported that the ship was stopped near Manzanillo, on the Atlantic side of the Panama Canal last week, and had crossed the Pacific Ocean on its way from Russia to Cuba, with its automatic tracking system switched off.

Panama's Security Minister Jose Raul Mulino, told the BBC, that the ship, which was carrying 250,000 bags of sugar, was halted last Wednesday as authorities suspected it might be transporting drugs, but the "resistance and violence from the crew" delayed the search.

Panama is reported to continue its search of the North Korean vessel.