North Korea were welcomed to the Asian Games on Thursday to the strains of "Gangnam Style", their athletes and officials gave a polite smile but put up a wall of stony silence in return.

North Korean athletes looked on blankly as breakdancers performed to the international hit by South Korean star Psy.

Their Singaporean, Chinese, Thai and Yemeni counterparts smiled and took pictures as dancers spun to the tune that has inspired more than two billion YouTube views. Only one North Korean woman dared the slightest handclap.

In contrast, the North Korean delegation belted out the words to their national anthem, "Aegukga", or Patriotic Song, as the isolated state's flag was hoisted in the athletes village along with those of the other new arrivals.

It was a unique occasion as normally anyone waving the North's flag or singing "Aegukga" in South Korea could face arrest under Seoul's strict national security law.

North Korea's presence has been one of the main talking points ahead of the Asian Games, which officially open in Incheon on Friday.

Their athletes and officials, mobbed by journalists at the flag-raising ceremony, appeared to be under instruction to stay tight-lipped. A couple of burly minders were on hand to fend off persistent reporters.

Flag Removed

Dressed in pristine white blazers and vivid blue trousers, and all wearing obligatory pin badges featuring North Korea's dead leaders Kim Il Sung and Kim Jong Il, the athletes responded to questions with polite smiles and total silence.

Only one official broke ranks, saying when asked how the delegation felt about the event: "Just look, you can see for yourself."

The North Koreans seemed bemused by the whole ceremony.

The athletes were accompanied on their walk to the flag plaza at the village by clowns on stilts and unicyles, as well someone dressed up as one of the Games mascots -- Chumoro, a cuddly pink seal.

As the North Koreans made their way from the plaza to their accommodation block they were surrounded by a rolling maul of camaramen, photographers and reporters -- but still kept mum.

The North Korean flag has already proved contentious at the Games, with organisers saying they will confiscate any found on South Koreans entering any of the venues.

Officials have also removed the North's flag from the streets around venues after anti-Pyongyang activists protested about having the North Korean emblem flying among them.

The North Korean flag is displayed along with other national flags at the official venues, and North Korean delegation members can bring their flags to events.

And the North delegation have already hung at least half a dozen giant flags from the windows of their apartment blocks in the athletes' village.

North Korea, who won six golds at the 2010 Asian Games, are sending 150 athletes to Incheon and almost as many many coaches and officials, one of the biggest delegations to the South since the Korean War was halted with an armistice in 1953.