'Apes' outmuscles 'The Purge' at box office.

• Position: News

NEW YORK -- The summer box office continued to lack mojo, as the R-rated ''Sex Tape'' failed to turn on moviegoers over a weekend where ''Dawn of the Planet of the Apes'' maintained its rule.

20th Century Fox's science fiction sequel outmuscled a trio of new films to top the North American box office for the second-straight week with $36 million, according to studio estimates Sunday. The acclaimed sequel to 2011's reboot of the chimp franchise has now made $139 million domestically in two weeks.

Its closest completion over the weekend was the home-invasion horror thriller ''The Purge: Anarchy,'' written and directed by James DeMoncaco. Universal's low-budget sequel to last year's surprise hit, ''The Purge,'' opened with $28.4 million, down from the $34.1 million the original scared up on opening weekend.

Nikki Rocco, head of distribution for Universal, though, noted the stronger competition this time around and the overall ''depressed'' business at movie theaters. Weekend revenue was down 24 percent from the same weekend last year...