Police say members of the FBI, Joint Terrorism Task Force and Bureau of Alcohol, Tobacco, Firearms and Explosives are on scene investigating. Omar said a worshipper saw a pickup truck speeding away afterward.
Trevin Miller, who lives across the street from the mosque, said he has heard occasional fireworks in the neighborhood, but nothing like Saturday morning's explosion.
This story has been corrected to show that the group is called the Muslim American Society of Minnesota, not the Muslim-American Association of Minnesota.
The FBI is helping police in Bloomington, Minnesota, try to determine the cause of an explosion early Saturday morning at a mosque in the city.
Omar said Dar Al Farooq has occasionally been the target of threatening e-mails and calls, usually telling members they don't belong. "I was shocked to learn this happened".
Neither the Bloomington Police Department, which initially responded to the explosion, nor the Federal Bureau of Investigation speculated on a motive for the incident, though some religious leaders and politicians condemned it as a possible hate crime.
Yasir Abdalrahman, a worshipper at the mosque, said the explosion was "unimaginable".
"We're here all together in order to defend the values of our country, the values of our faith, the values of our people", said Hamdy El-Sawaf, president of the board of the Islamic Community Center of Minnesota. "Every other American should be insulted by this".
The mosque serves as a religious center and community organizing platform for Muslim activists and leaders in the area, according to the society.
The Minnesota section of the Council on American-Islamic Relations additionally said it was putting forth a $10,000 compensate.
The council urged USA mosques to increase their security following the Bloomington incident. Hussein said a "standing opposition group" has regularly protested against the mosque - and sometimes its mere existence - since it opened in 2011.
If the attack was motivated by anti-Muslim bias, it would represent "another in a long list of hate incidents targeting Islamic institutions nationwide in recent months", CAIR-MN civil rights director Amir Malik said.