CHICAGO — The discovery of apparent bullet holes at a Northwest Side mosque has triggered calls for a hate crime investigation.

The damage, found over two days last week at the Muslim Community Center, has left members of the local Muslim community feeling targeted, according to the Chicago office of the Council on American-Islamic Relations.

Ahmed Rehab, executive director of CAIR-Chicago, said in a statement that it was unclear whether the holes were caused by a firearm, a BB gun or something else.

"What seems clear is that the person who inflicted this damage on a Muslim house of worship did not come in peace," Rehab said. "This attack is not just on a building; it is an attack on the Muslim community’s safety and right to worship freely.”

The damage to front windows and doors of the mosque at 4380 N. Elston Ave. was reported early Tuesday morning, initially categorized as property damage.

Mosque administrators have reported the incident to both Chicago police and the FBI and encouraged everyone to remain vigilant but not to panic.

Local CAIR representatives called for greater awareness of the "growing threats to religious communities" in the Chicago area.

According to CAIR, the largest Muslim civil rights advocacy group in the country, the number of complaints of anti-Muslim and anti-Palestinian incidents increased by 69 percent to 4,951 from January to June of this year, compared to the first half of last year.

“This is the second attack on Muslim property in recent days that the police have chalked down as mere destruction of property," CAIR-Chicago staff attorney Joseph Milburn said in a statement, "hate motivation should not be ruled out without a thorough investigation”.

The damage at the mosque comes days after a window displaying a Palestinian flag was smashed at a coffee shop in the Uptown neighborhood. There was nothing stolen in that incident.