A South Korean developer said yesterday it would not alter the design of a twin-tower project despite complaints in the United States that it mimics the explosions at New York's World Trade Center in 2001.

The towers, one with 54 floors and the other with 60, are designed by Dutch architects MVRDV and will be built at the entrance to Seoul's redeveloped Yongsan business district by 2016.

The towers will be connected midway up by a cloud-shaped bridging section that will house amenities including sky lounges, a swimming pool and restaurants.

But families of victims of the 9/11 attacks see a marked resemblance between the project known as The Cloud and the clouds of debris that billowed from the World Trade Center after hijacked airliners ploughed into the towers.

"Allegations that it (the design) was inspired by the 9/11 attacks are groundless,"said White Paik, spokesman for the Yongsan Development Corporation."There will be no revision or change in our project," he said adding that construction would begin in January 2013 as scheduled.

MVRDV said it "regrets deeply" any painful connotations. "It was not our intention to create an image resembling the attacks nor did we see the resemblance during the design process," it said in a statement on its website. "We sincerely apologise to anyone whose feelings we have hurt," it added.