"The Dark Knight Rises" is still unshaken on the top of North American box office. The third Batman film from Christopher Nolan adds an estimated $64.1 million on its second weekend to secure the champion title, though it suffers a big drop of 60% compared to its opening weekend's gross, AceShowbiz said.

After its ten-day run, the superhero action film has collected a total of $289.1 million domestically. The number is slightly below its predecessor "The Dark Knight", which had earned $313.8 million at the same point in its run. Overseas, the Christian Bale-starring movie has grossed $248.2 million, making its total worldwide haul to $537.3 million.

Also staying on its last week's position is "Ice Age: Continental Drift", which still bows on No. 2. The fourth installment of the 20th Century Fox animated film franchise grosses approximately $13.3 million on its third weekend.

Meanwhile, newcomers "The Watch" and "Step Up Revolution" fail to attract many moviegoers as they have so-so debuts. The former enters the chart on the third place with around $13 million, while the latter trails on the fourth place with an estimated $11.8 million.

Rounding up the top five is "Ted". The R-rated comedy from director/writer Seth MacFarlane is forced to step down one place from No. 4 to No. 5 with an addition of around $7.4 million to its domestic cume.