Jade Yorker stars in Gridiron Gang alongside former wrestler The Rock

Gridiron Gang, starring Dwayne "The Rock" Johnson, took $15m (�8m) in what was a slow weekend for US cinemas.

The Black Dahlia, based on the 1947 murder of a Hollywood actress, opened at number two with $10.4m (�5.5m).

Everyone's Hero, directed by the late Christopher Reeve, opened in third place with an estimated $6.2m (�3.3m).

The animated film tells the story of a boy who travels across the country to return a baseball bat to baseball legend Babe Ruth.

Low takings

The Last Kiss, a film about a group of men in their 20s who are afraid to commit, debuted in fourth place with $4.7m (�2.5m).

The only non-new entry in the top five was last weekend's box office winner The Covenant, which slipped to fifth place.

Hollywoodland, starring Ben Affleck as original Superman actor George Reeves who apparently shot himself in 1959, slipped from second place to number nine.

For the second consecutive weekend, the top 12 films fared less well than they did across the same weekend last year, taking $62m (�33m), compared to $70.6m (�37.8m).

"With two LA noir films and two football movies, audiences may be feeling like they've seen some of this before and may not be coming out in bigger numbers," said Paul Dergarabedian, president of Exhibitor Relations, which compiles box office statistics.

However, studio revenues have increased 6.2% from last year, with attendance up by 3%, according to Exhibitor Relations.