A trio of animated secret agent guinea pigs has broken the spell of Harry Potter at the top of the US box office, according to early estimates. G-Force, a Disney live action and computer-generated animation, took $32.1m (£19.4m) over the weekend. Harry Potter and the Half-Blood Prince has dropped to second place with a $30m (£18.1.m) haul in its second weekend. Internationally, the movie - the sixth in the Potter franchise - has raked in $627.1m (£380.2m). The film opened with $79.5m (£48.4m) in the US last weekend. Romantic comedy The Ugly Truth, starring Katherine Heigl and Gerard Butler, took $27m (£16.3m) to make the third spot on its opening weekend. Horror movie Orphan debuted at number four with $12.7m (£7.7m). And Ice Age: Dawn of the Dinosaurs dropped from second place to fifth, with takings of $8.2m (£4.9m). US BOX OFFICE FIGURES 1. G-Force -$32.1m 2. Harry Potter and The Half-Blood Prince - $30m 3. The Ugly Truth - $27m 4. Orphan -$12.7m 5. Ice Age: Dawn of the Dinosaurs - $8.2m Source: BBC