SEOUL (AFP) - South Korea on Wednesday welcomed the seizure off Panama of a North Korean ship suspected of carrying weapons, urging the United Nations take up the case.

"The government appreciates the Panamanian government's stoppage of a North Korea vessel carrying a suspicious cargo," a foreign ministry official said.

"If the shipment tuns out to be in breach of UN resolutions, we expect the UN Security Council's sanctions committee to take relevant steps expeditiously", the official said.

Panama said on Tuesday it had found military equipment, which it believed to be missiles, after impounding the ship and conducting a drugs search.

Cuba said that the weapons found on the ship were "obsolete" Soviet-era arms that the communist island had sent to Pyongyang for repair.

Panama earlier on Tuesday urged UN inspectors to scrutinise the cargo, which could constitute a violation of the strict arms sanctions imposed on North Korea over its nuclear programme.

Analysts in Seoul said the North, which successfully launched a satellite into orbit last year, is well capable of selling missile repair services abroad.

"But we cannot rule out the possibility of North Korea importing parts for its own Soviet-era missiles", Mr Shin In Kyun, President of the private Korea Defence Network, told AFP.

Dr Lee Ho Ryung, an analyst with the Korea Institute for Defence Analyses, said she was sceptical about Cuba's announcement.

"It's hard to understand the North was taking such high risks just to repair another country's missiles at a time when it is under tight international sanctions."

Cuba, one of North Korea's few allies, claimed the shipment as its own, with the foreign ministry listing 240 tonnes of "obsolete defensive weapons", including two anti-aircraft missile systems as being on board.

There were also "nine missiles in parts and spares", various Mig-21 aircraft parts and 15 plane motors, "all of it manufactured in the mid-20th century" and "to be repaired and returned to Cuba".

UN sanctions bar the transport of all weapons to and from North Korea apart from imports of small arms. Several of the country's ships have been searched in recent years.

In July 2009, a North Korean ship heading to Myanmar, the Kang Nam 1, was followed by the US Navy due to suspicions it was carrying weapons. It turned around and headed back home.

Pyongyang has yet to comment on the latest incident