Actress Gyllenhaal in 9/11 outcry

The 27-year-old is the sister of Donnie Darko actor Jake Gyllenhaal

Actress Maggie Gyllenhaal has prompted outcry after she remarked that the US was "responsible in some way" for the terror attacks of 11 September 2001.

Gyllenhaal was speaking at an interview promoting her new film, The Great New Wonderful, about people living in New York in the aftermath of 9/11.

In a subsequent statement issued by her publicist, she defended the comment.

"Not to have the courage to ask these questions of ourselves is to betray the victims of 9/11," the 27-year-old said.

In the statement, Gyllenhaal said 11 September was "an occasion to be brave enough to ask some serious questions about America's role in the world".

It is always useful as individuals or nations to ask how we may have knowingly or unknowingly contributed to this conflict Maggie Gyllenhaal

She added: "It is always useful as individuals or nations to ask how we may have knowingly or unknowingly contributed to this conflict."

She also expressed her grief for "everyone who suffered and everyone who died in the catastrophe".

A fan site was inundated with angry messages following the actress's remarks, prompting the editor of the site to temporarily close the forum.

Gyllenhaal lives in Manhattan where The Great New Wonderful is currently being shown at the Tribeca Film Festival.

The film festival was co-founded by Robert De Niro to help revitalise the city following the 11 September terror attacks.

The actress's previous credits include Mona Lisa Smile, opposite Julia Roberts, and Donnie Darko, in which she starred alongside her brother, actor Jake Gyllenhaal.