New York City police searched on Sunday for a suspect in the shooting of a Muslim cleric and his associate.

The cleric and his companion were killed while walking together along a city street after attending prayers at a nearby mosque, authorities said.

A lone armed man approached the two from behind and shot both in the head at close range in the Ozone Park neighborhood in Queens, police said in a statement.

They cited witnesses’ statements and video surveillance footage for details of the attack in the largely working-class area, home to many Muslims of Bangladeshi heritage.

Witnesses told police they saw the assailant, dressed in a dark shirt and blue shorts, fleeing the shooting scene with a gun in his hand, police said.

Early on Sunday, police released a sketch of a male suspect with dark hair, a beard and glasses. Police described him as having a medium complexion. He appeared to be in his 30’s or 40’s.

The victims, identified as Imam Maulama Akonjee, 55, and Thara Uddin, 64, were both wearing religious garb at the time of shooting, police said.

They were found by police lying in the street and transported to a local hospital where they were pronounced dead.

The motive for the shooting was not immediately known and no evidence has been uncovered that the two men were targeted because of their faith, but police were not ruling out any possibility, a department spokeswoman said.

Akonjee was carrying $1,000 with him at the time of the attack but the money was not taken, the New York Times reported.

City Council Speaker Melissa Mark-Viverito condemned the attacks and called on more witnesses to come forward.

“I am shocked and saddened at the murders,” Mark-Viverito said in a statement. “This kind of hate has no place in our communities.”

New York City Mayor Bill de Blasio was closely monitoring the shooting investigation, a spokesman for the mayor said in a statement, and assured the public “the NYPD will stop at nothing to ensure justice is served.”

The Council on American-Islamic Relations, a Muslim civil rights and advocacy group known by the acronym CAIR, said Uddin was an associate of the imam.

“These were two very beloved people,” Afaf Nasher, executive director of the New York chapter of CAIR, told Reuters.