Expect bloody competition for the top spot at the weekend box office.

Lionsgate's horror sequel Saw VI does battle with Paramount's similarly targeted supernatural thriller Paranormal Activity as three other wide releases hit multiplexes: Fox Searchlight's Hilary Swank-starring Amelia, Summit's animated feature Astro Boy and Universal's John C. Reilly-toplined Cirque du Freak: The Vampire's Assistant.

The Saw sequel had been expected to perform much in line with franchise predecessors, bowing just north of $30 million to top the weekend rankings. But Paranormal has been doing abnormally strong business, first in limited release and last weekend from a barely wide 760 playdates.

Paranormal expands again to nearly 2,000 engagements Friday, creating audience overlap with the Lionsgate movie. But though both pictures carry R ratings, Saw support comes mostly from younger males, while the notably non-gory Paranormal plays best among younger females.

All things considered, the Saw sequel, set for 3,036 engagements, might find it tough to open higher than $25 million-$30 million, and Paranormal should fetch just below that range.

The PG-rated Amelia Earhart biopic Amelia should play broadly and vie for date-night coin Saturday. But its relatively modest distribution in about 800 theaters suggests a debut in the range of $8 million-$10 million.

Critics' support could be key to opening prospects for the Mira Nair-helmed pic, and positive word-of-mouth will be important further along. Early reviews have been lukewarm.

Inspired by the 1960s TV cartoon series, the PG-rated Astro Boy boasts 3,014 playdates. Young boys and their dads form a target audience, with the film likely to register $10 million or more through Sunday. Imagi Studios produced the 2D-animated pic at an estimated cost of $65 million, with Summit distributing.

Cirque du Freak is based on a series of books for tween and young teenage boys. A $10 million-plus bow looks likely for the PG-13 film, which circulates in 2,754 locations.

The previous weekend's No. 1 movie, Warner Bros.' Spike Jonze-directed fantasy Where the Wild Things Are, will be watched closely after opening with a better-than-expected $32.7 million. Adults outnumbered kids at its opening performances, so Wild Things might not display the marketplace hold of a typical family film.

On an industrywide basis, the weekend will be measured against a big $134 million session last year topped by High School Musical 3: Senior Year ($42 million) and Saw V ($30 million). That could prove a tough comparison, but the market has been strong of late, with year-over-year upticks each of the past two weekends.

Year to date, 2009 is pacing 5 percent ahead of 2008 at $8.06 billion.