Muslim leaders are trying to strengthen Sunni-Shi'ite ties in the US, hoping to head off conflicts between the faith's two major sects and get American Muslims to focus on common problems. With sectarian divisions fueling violence in Iraq, Sunnis and Shi'ites in the US are increasingly wary of a spillover effect. In one public example, leaders from both traditions have launched "Intra-faith Code of Honor" campaigns in three cities with major Muslim populations. So far, 20 Sunni and Shi'ite leaders in Southern California have signed the first such code. The document denounces "takfir" - the labeling of another Muslim as a nonbeliever - forbids hateful speech about revered figures and urges debates at the scholarly level, not the street level. Similar agreements are expected to be completed this month in Detroit and Washington, D.C. "As technology has made information from across the globe and information from historical conflicts more available, people have been pondering their self-identity," said Salam Al-Marayati, executive director of the Los Angeles-based Muslim Public Affairs Council, which is helping organize the effort. "That has brought a requirement to appreciate the nuances, but it's also brought challenges." Those include questions over how prayer is conducted, said Dr. Maher Hathout, spokesman for the Islamic Center of Southern California, which eschews Sunni or Shi'ite labels. The honor code urges congregations to follow worship traditions of whichever groups is in the majority locally, an issue that has arisen over the Shi'ite custom of combining some of Islam's five daily prayers, Hathout said. Another concern is keeping virulently sectarian literature from the Middle East out of American mosques. "As much as we can make clear the Muslim-American identity is not a natural extension of the Middle East, the better off we'll be," he said. Other steps under discussion include gathering national Sunni and Shi'ite leaders, workshops at mosques and political analysis of Middle East trends "so people are not caught off guard," Al-Marayati said. Although no reliable data exists, it is presumed America's estimated 2 million to 6 million Muslims are 85 percent to 90 percent Sunni and 10 percent to 15 percent Shi'ite, reflecting the global breakdown. Conflicts have been few, scholars say, in part because this country's Muslim population is relatively small. In addition, immigrant US Muslims tend to be prosperous and are melting into society instead of clustering in poorer neighborhoods, which has caused conflict in Europe.