"We know particularly with anti-Muslim websites that they aim to desecrate mosques with pig’s blood, and also dogs, this definitely was a concern for us," said Jaylani Hussein, Executive Director of the Minnesota chapter of the Council on American-Islamic relations (CAIR-MN).

Eric Chaloux/KSTP

CAIR-MN officials asked police to investigate a possible bias motive for the intrusion.

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Authorities in the city have stepped up patrols around the mosque which is located on 4th Avenue South, just off the St. Cloud State University campus.

"If this was done with intentions to harass, or intentions to cause fear, we are going to pursue it that way if that's what we end up finding,” said St. Cloud Police Assistant Chief Jeffery Oxton. “If there's another explanation for it, we'll go down that road as well."

The unidentified man wearing a ball cap, t-shirt and sunglasses walked through the mosque before he was noticed by members who tried to see what he was doing, but he didn’t stop to talk according to witnesses.

"To be honest with you since this incident, the community has learned about it, there's an increased fear about what is happening," said Imam Ahmed Mohamed.

Imam said there are heightened tensions in the area in recent weeks.

"Since we've come to this country we've felt safe, but these types of incidents create fear-- but we have to overcome it," Mohamed said.

There's been fear among members of the Muslim community in St. Cloud recently. Two weeks ago, a New York Times article highlighted some anti-Somali sentiment in the city over the placement of refugees. According to U.S. Census Bureau estimates, the Somali population in St. Cloud has increased significantly over the past decade.

Several years ago, vandals struck this same mosque by breaking out windows.

"The message we are trying to get out is for people to say knock this off, this is unacceptable behavior and we are not going to tolerate this type of harassment," Hussein said.

At last check, St. Cloud police had not identified the man in the video wanted for questioning.