WASHINGTON, March 13: Muslim advocacy groups on Thursday urged the FBI and other US security agencies to protect them against hate crimes after an attack on a mosque in Chicago.

More than 100 Muslims were praying inside when the mosque was attacked on Wednesday.

“It was a deliberate attempt to kill worshippers because those praying were clearly visible to the attackers through the large windows of the mosque,” says Abdul Hameed Dogar, director Islamic Foundation, Chicago.

Witnesses told police investigators that worshippers heard two loud bangs just after evening prayer at the Islamic Foundation in Villa Park, near Chicago, one of the largest mosques and Islamic schools in America.

When the worshippers rushed to investigate the bangs, they saw two bullet marks on a window, witnesses said.

Villa Park police detective John Szkolka told the Council on Arab-Islamic Relations he is following “some leads” in the case. Szkolka said the attack was “almost certainly” bias-related.

This was not the first such attack on the mosque. In 1999, vandals threw a chunk of concrete through a glass door and broke a window. Other incidents of vandalism occurred while the mosque was under construction. Following the 9/11 terror attacks, the mosque received a number of threats.

“We are thankful that no one was hurt in last night’s attack. This incident is just the latest in a series of assaults on and threats against American Muslims in recent weeks,” said Omar Haydar, a Muslim community leader in Chicago.

“We believe the increase in hate crimes is directly related to the drumbeat of pro-war and anti-Muslim rhetoric in our society. Local law enforcement agencies should offer increased protection to Muslim communities and their institutions during this time of crisis,” he added.

Haydar noted that earlier this week, death threats were made against Muslim students.