Muslim immigrant men have been accused of six "honor killings" in the United States in the past two years, prompting concerns that the Muslim community and police need to do more to stop such crimes.

"There is broad support and acceptance of this idea in Islam, and we're going to see it more and more in the United States," says Robert Spencer, who has trained FBI and military authorities on Islam and founded Jihad Watch, which monitors radical Islam.

Honor killings are generally defined as murders of women by relatives who claim the victim brought shame to the family. Thousands of such killings have occurred in Muslim countries such as Egypt, Jordan, Pakistan and Palestinian territories, according to the World Health Organization.

Some clerics and even lawmakers in these countries have said families have the right to commit honor killings as a way of maintaining values, according to an analysis by Yotam Feldner in the journal Middle East Quarterly.

In the USA, police allege the latest "honor killing" was that of Noor Almaleki, 20, who died Nov. 2 after she and her boyfriend's mother were run over in a Peoria, Ariz., parking lot. Prosecutors charged Almaleki's father, Faleh Almaleki, with murder, saying the Iraqi immigrant was upset that his daughter rejected a husband she married in Iraq and moved in with an American.

"By his own admission, this was an intentional act, and the reason was that his daughter had brought shame on him and his family," says Maricopa County prosecutor Stephanie Low, according to The Arizona Republic.

Many Muslim leaders in the USA say that Islam does not promote honor killings and that the practice stems from sexism and tribal behavior that predates the religion.

"You're always going to get problems with chauvinism and suppressing vulnerable populations and gender discrimination," says Salam Al-Marayati, executive director of the Muslim Public Affairs Council.

Not all agree. Zuhdi Jasser says some Muslim communities have failed to spell out how Islam deals with issues that can lead to violence.

"How should young adult women be treated who want to assimilate more than their parents want them to assimilate?" asks Jasser, founder of the American Islamic Forum for Democracy, which advocates a separation of mosque and state. "How does an imam treat a woman who comes in and says she wants a divorce ... or how to deal with your daughter that got pregnant, and she's in high school?"

Phyllis Chesler, who wrote about honor killings in her book Woman's Inhumanity to Woman, says police need to focus on the crimes' co-conspirators if they wish to reverse the trend. Before 2008, there were six honor killings in the USA in the previous 18 years, according to her research.

"It's usually the father, brother or first male cousin who is charged with the actual shooting or stabbing, (but not) the mother who lures the girl home," Chesler says. "The religion has failed to address this as a problem and failed to seriously work to abolish it as un-Islamic."

Jasser says his community needs to address how to treat young women who want to assimilate. "Until we have women's liberation ... we're going to see these things increase."