The vampire-themed romance "Twilight" series has been listed among the top 10 books that U.S. schools and public libraries were asked to remove from their shelves in 2009, according to reports of Reuters.
This Stephenie Meyer's bestseller occupied the fifth place on the list which rated by the American Library Association (ALA) for the first time.
The ALA said that the vampire stories were challenged for being sexually explicit, and having religious views unsuitable for their age group.
"Vampire novels have been a target for years and the 'Twilight' books are so immensely popular that a lot of the concerns people have had about vampires are focused on her books," says Barbara Jones, director of the association's Office for Intellectual Freedom.
The "ttyl" series, which came top of the 2009 list, was challenged for nudity, offensive language and drugs.
The children's picture book "And Tango Makes Three" about two male penguins adopting a baby, and teen novel "The Perks of Being a Wallflower" took the No. 2 and No. 3 spots in 2009.
Harper Lee's 1960 Pulitzer Prize winning classic "To Kill a Mockingbird" came fourth because of challenges on the grounds of racism and language.
It is worth mentioning that J.K. Rowling's "Harry Potter" series didn't appear on the top 10 list. But the boy wizard's adventure stories landed atop the 100 most frequently challenged books of the 2000-2009 decade.
The top 5 most frequently challenged books of 2009 were:
1: "ttyl", "ttfn", "l8r", "g8r" (series) by Lauren Myracle
2: "And Tango Makes Three," by Pater Parnell and Justin Richardson
3: "The Perks of Being a Wallflower," by Stephen Chbosky
4: "To Kill A Mockingbird", by Harper Lee
5: "Twilight" (series), by Stephenie Meyer