Dutch practice MVRDV has been forced to apologise after its design for a pair of residential towers in South Korea was likened to images of the 9/11 twin towers coming down.

Called the Cloud, the project was presented to developer Dream Corporation by the Rotterdam firm in the South Korean capital Seoul last Wednesday.

The larger tower is 300m tall with the smaller tower measuring 260m. Both are connected by what the architect calls a “pixelated cloud of additional program”.

But the firm has been stung by criticism from people in the US and its native Holland after it decided to post the images on its Facebook page. Critics said the towers looked like the twin towers of the World Trade Centre beginning to collapse following the terrorist attacks.

MVRDV spokesman Jan Knikker told BD the practice had been sent abusive emails, and staff had been verbally abused over the phone. One poster on the US conservative website, Blaze, said: “Why don’t they just build a mosque on the top too?” And another added: “This is disrespectful at the least and should not be able to be done.”

Knikker added:  “We’ve had quite a lot of calls from angry Americans saying it’s a disgrace. 9/11 was not the inspiration behind the design, the inspiration was a real cloud.”

He said the firm had not meant to cause offence and denied it was anti-American, adding that it had worked for free on the rebuilding of New Orleans in the wake of 2005’s Hurricane Katrina. “It was not our intention to create an image resembling the attacks nor did we see the resemblance during the design process,” he added. “We sincerely apologise to anyone whose feelings we have hurt.”

He added that Dream Corporation had picked the Cloud design from a number of options it was given and said it was the client’s decision as to whether it would now look at an alternative.

The towers are part of a masterplan designed by US architect Daniel Libeskind – the architect behind the masterplan of the Word Trade Centre site in New York – while public gardens have been designed by another US practice Martha Schwartz.