LOS ANGELES, Aug. 24 (Xinhua) -- "Tropic Thunder" was the number one movie again at the box office in North America this weekend, as the action comedy from actor-director Ben Stiller took in an estimated 16.1 million dollars over the three-day period.

    That would make the DreamWorks production, which is in its second week in release, to remain at the top of box offices in the United States and Canada for the second weekend in a row, according to Los Angeles-based box office tracking firm Media By Numbers Sunday.

    A pair of new releases took the next two spots at the box office, as Sony Pictures' sorority-themed comedy "The House Bunny" opened with 15.1 million dollars and Univeral's thriller "Death Race" debuted with 12.4 million dollars over the weekend.

    Hollywood's biggest success this summer, Warner Bros.' Batman sequel "The Dark Knight" slipped to fourth with 10.3 million dollars in ticket sales, but the film was closing in on a half-billion dollars in North America in its sixth week of release after it became the second-biggest domestic release in history last week.

    Total box office revenues so far this summer are 3.9 billion dollars, slightly higher than that in same period last summer, when Hollywood saw a record of 4.16 billion dollars in the lucrative season. But higher ticket prices mean the actual summer admissions are down about 3 percent this year.