Los Angeles - The Hollywood war-movie spoof Tropic Thunder remained atop the North American box-office rankings for a second straight weekend with three-day ticket sales of 16.1 million dollars, according to preliminary studio estimates issued Sunday.

The film stars Ben Stiller, Jack Black and Robert Downey Jr as three pampered actors filming a Vietnam War movie, only to be captured by real drug traffickers in the jungle.

The movie debuted last weekend in first place and repeated the feat in the Friday-Sunday period despite tough competition from new premiers this weekend. (dpa)