The Council on American-Islamic Relations (CAIR) is offering a reward of $10,000 (£7,664) for information that can identify those behind an attack at a mosque in Minnesota.
A blast occurred at the Dar Al-Farooq Islamic Center in Bloomington on Saturday (5 August) morning.
Witnesses said someone threw an improvised explosive device from a vehicle – believed to be a pickup truck – at the imam's office.
There were between 15 and 20 people gathered at the mosque for morning prayers when the explosion occurred, according to AP.
The blast did not injure people, but it damaged a room in the building.
"We hope a reward will help law enforcement authorities quickly apprehend the perpetrator of this act of violence targeting an American house of worship,"Amir Malik, Civil Rights Director at the CAIR's Minnesota section, said in a statement.
"If a bias motive is proven, this attack would represent another in a long list of hate incidents targeting Islamic institutions nationwide in recent months."
The organisation also urged mosques and Islamic centres across the country to step up security measures.
The FBI is conducting an investigation into the blast. Authorities have recovered parts of the device and are figuring out how it was put together.
The mosque primarily serves worshippers from the area's large Somali community.
Mohamed Omar, the mosque's executive director, said the centre had received threatening calls and emails in the past.
Speaking about the attack, he told the Star Tribune: "It was 5am. The whole neighbourhood was calm. People were supposed to be sleeping, that how peaceful this should be. I was shocked to learn this happened".
Yasir Abdalrahman, a worshipper at the mosque, said the explosion was "unimaginable".
"We came to this country for the same reason everyone else came here: freedom to worship," he explained.
"And that freedom is under threat. Every other American should be insulted by this."
Spike of attacks since 'November election'
CARI claimed attacks against Muslims have increased in the past year.
"CAIR has noted an unprecedented spike in hate incidents targeting Muslims and other minority groups since the November 8 election" the organisation explained.
It added that it had recorded "a 57% increase in anti-Muslim incidents in 2016" and a "44% increase in anti-Muslim hate crimes during the same period."
Last November's election saw the emergence of TV personality and magnate Donald Trump as the new US President.
The head of state has often sparked criticism for his divisive remarks and his policies aiming at curbing immigration.
Earlier this year, lower courts in the US blocked a proposition by Trump to impose a 90-day travel restriction on people from Muslim-majority countries Iran, Libya, Somalia, Sudan, Syria and Yemen, along with a 120-day entry ban on refugees.
The Trump administration said the ban was necessary on grounds of national security and to allow the implementation of new immigration vetting procedures.
In June, the supreme court partly lifted the ban, arguing it could be enforced in case people who applied from the targeted countries lack "a credible claim of a bona fide [authentic] relationship with a person or entity in the United States".