Image copyright Handout Image caption Bradley Cooper has been nominated for best actor at the Oscars for his role in American Sniper

The release of the film American Sniper has led to an increase in threats against Muslims in the US, according to an Arab-American civil rights group.

The American-Arab Anti-Discrimination Committee (ADC) has written to director Clint Eastwood and star Bradley Cooper.

Their film is based on US soldier Chris Kyle's service in Iraq from 2003-09.

The ADC said a "majority of the violent threats we have seen over the past few days are result of how Arab and Muslims are depicted in American Sniper".

The organisation, which describes itself as the largest Arab civil rights organisation in the US, said it had collected "hundreds of violent messages targeting Arab and Muslim Americans from movie-goers", mainly from Facebook and Twitter.

The letter asked Eastwood and Cooper to speak out against such messages "in an effort to reduce the hateful rhetoric".

"Your visibility, influence, and connection to the film would be a tremendous force in drawing attention to and lessening the serious dangers facing the respective communities," ADC president Samer Khalaf wrote.

Media playback is unsupported on your device Media caption Bradley Cooper plays Navy Seal Chris Kyle (Courtesy Warner Bros)

Jack Horner, a spokesman for the Warner Bros film studio, which released the film, told the Reuters news agency that the company "denounces any violent, anti-Muslim rhetoric, including that which has been attributed to viewers" of the film.

He added: "Hate and bigotry have no place in the important dialogue that this picture has generated about the veteran experience."

Spokespeople for Eastwood and Cooper had no immediate response to requests for comment, Reuters news agency reported.

American Sniper has been a major hit in North America, exceeding box office predictions by taking $90m (£59m) in its opening weekend - a record for a January release. It also has six Oscar nominations.

Film controversy

But it has caused controversy. Some have hailed its portrayal of Kyle as a war hero, but others have criticised it for glorifying violence and for Kyle's attitude towards his victims.

Kyle, a Navy Seal, served four tours of duty in Iraq and killed more than 160 people, making him the most deadly sniper in American history.

The film is based on his book, also titled American Sniper, in which he claimed to have no regrets and referred to those he killed as "savages".

Kyle was killed in February 2013 on a firing range in his home state of Texas.