Muslim sectarian antagonism was reported in the Holy City of Mecca in Saudi Arabia Oct. 16 when a group of Lebanese-Australian Sunni Muslims allegedly attacked men and threatened to rape women of an American Shiite Muslims group from Detroit.

Complaints to the Saudi Arabian police by the group got a lukewarm response, with officers even deleting the video clip of the alleged incident. The attack, known as the most extreme and frightening experience, has left the American group shaken.

Since the civil war in Syria began, age-old antagonism between the two Muslim sects Shias and Sunnis has become more pronounced in recent years. In Syria, the government backed by Shiites is pitted against Sunni rebels supported by Saudi Arabia.

Detroit Free Press, which first reported the incident, quoted a witness saying one of the members of the American Shiite group was strangled, until his face turned blue.

The American Shia Muslims on Haj were led by Imam Hassan Al-Qazwini of the biggest mosque of Detroit. Free Press reported that "the group included three women from the Amen family who were featured in the reality TV show, "All-American Muslim."

On the evening of Oct. 16, some members walked into the tent occupied by the group and confronted the Americans asking them if they were Shias. Upon confirmation, they were immediately attacked with the members shouting, "Kill them all. Kill the Shia."

Some of the Sunni attackers then ran towards the women's tents telling them to leave in 15 minutes or they will get raped.

While members of the Shias community have been harassed in the past, the Oct. 16 incident was reported to be much more extreme and frightening.

The Shiite group alleged that the Saudi Arabian authorities did not take the compliant seriously and deleted their video.

The Free Press quoted U.S. State Department official as saying, "We are concerned by reports that a group of U.S. citizens was attacked ... at a campsite for Haj pilgrims located outside of Mecca. We take these reports seriously and are committed to the protection of U.S. citizens travelling and residing abroad."

The State Department has taken up the issue with the Saudi Arabian Haj and interior ministries who "have confirmed that they are investigating" the incident.