American Gangster has debuted at number one in the US box office chart.

The Ridley Scott-directed film knocked Saw IV off the top spot after the horror movie had spent just one week at number one.

There were other new entries for animated comedy Bee Movie and John Cusack drama Martian Child at numbers two and seven in the chart.

The top ten movies in full:

1. (-) American Gangster - $46,344,450
2. (-) Bee Movie - $39,100,000
3. (1) Saw IV - $11,010,000
4. (2) Dan In Real Life - $8,125,000
5. (3) 30 Days of Night - $4,000,000
6. (4) The Game Plan - $3,853,000
7. (-) Martian Child - $3,650,000
8. (6) Michael Clayton - $2,900,000
9. (5) Why Did I Get Married? - $2,730,000
10. (7) Gone Baby Gone - $2,400,000