The two men were both shot in the head after coming out of prayers from the Al-Furqan Jame Mosque in Ozone Park, New York.
An imam and his assistant were both shot in the head and killed in New York on Saturday, police said, in an attack with unclear motives.
The cleric, who police identified as Maulana Akonjee, 55, and his 64-year-old associate Tharam Uddin, were both shot in the head at close range at about 17:50 (GMT) after leaving the Al-Furqan Jame Mosque in the Ozone Park neighborhood.
Both men were wearing religious garb at the time they were shot.
The motive for the shooting was not immediately known and no evidence has been uncovered so far that the two men were targeted because of their faith, said Tiffany Phillips, a spokeswoman for the New York City Police Department.
But police were not ruling out any possibility, she added.
Akonjee, however, had more than $1,000 on him at the time of shooting, but the cash was not taken, The New York Times reported.
Both men were pronounced dead later Saturday, an administrator at Jamaica Hospital said.
Police have yet to identify a suspect, but Phillips said witnesses said they saw a lone armed assailant fleeing the scene on a blistering hot summer afternoon.
Akonjee was described as a peaceful man who was beloved within Ozone Park's large Muslim community.
"He would not hurt a fly," his nephew Rahi Majid, 26, told the New York Daily News.
"You would watch him come down the street and watch the peace he brings."
Video footage posted on YouTube showed members of the Bangladeshi community who oray at the mosque gather near the site of the shooting, with one of them telling the crowd that it was a hate crime.
"We feel really insecure and unsafe in a moment like this," Millat Uddin, an Ozone Park resident told local media.
"It's really threatening to us, threatening to our future, threatening to our mobility in our neighbourhood, and we're looking for justice."