A movie about the power of prayer, made by Christian film-makers with an all-Christian cast, has gone to the top of the North American box office chart.

War Room, about a troubled family who meet a lady with a prayer room, cost $3m (£2m) to make and earned $9.3m (£6.1m) between Friday and Sunday.

It marks the acting debut of Priscilla Shirer, a spiritual speaker and author.

Straight Outta Compton, a biopic of rap group NWA, fell one place to two after spending three weeks in the top spot.

War Room was written and directed by brothers Alex and Stephen Kendrick, who have been dubbed "the Spielbergs of Christian cinema" by Variety magazine.

"We didn't wake up one day wanting to make a movie about a 75-year-old woman's prayer closet," Stephen Kendrick said. "We asked God to order our steps and the ideas came."

Straight Outta Compton made $8.9m (£5.8m) on its third weekend in US and Canadian cinemas, according to studio estimates.

A Walk in the Woods, an adaptation of a book by travel writer Bill Bryson starring Robert Redford and Nick Nolte, is ranked third with $8.1m (£5.3m).

Mission Impossible: Rogue Nation was fourth in this week's chart, followed by new release The Transporter: Refuelled.

The weekend was also a significant one for dinosaur blockbuster Jurassic World, which has now made more than $1 billion (£655m) outside North America.

According to the Hollywood Reporter, it is only the fourth film to achieve this feat, after Avatar, Titanic and this year's Fast & Furious 7.