Two Bangladeshi nationals including an imam were shot dead by a gunman in New York on Saturday.

They were identified as Alauddin Akonjee, 55, imam of Al-Furqan Jame Mosque in Ozone Park, and his associate Tara Uddin, 64, reports Bangla daily Prothom Alo.

A lone gunman shot them when they were walking together following afternoon prayers at a mosque in the New York City borough of Queens, Reuters reports quoting authorities.

The gunman approached the pair from behind and shot both in the head at close range at about 1:50pm (EDT) on a blistering hot afternoon in the Ozone Park neighborhood, police said in a statement, adding that no arrests had been made.

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, said Tiffany Phillips, a spokeswoman for the New York City Police Department. Even so, police were not ruling out any possibility, she added.

The victims were both wearing religious garb at the time of shooting, police said.

The NYPD declined to describe the connection between the victims but the Council on American-Islamic Relations said Uddin was an "associate" of the imam.

“The perpetrator of these senseless killings must be swiftly apprehended and face the full force of the law,” Afaf Nasher, executive director of the Muslim advocacy group's New York chapter, said in a statement.

Locals gather the place where the incident took place. Photo: Reuters

The men were transported to Jamaica Hospital Medical Center and died "while life-saving procedures were being performed," said Andrew Rubin, a hospital spokesman.

The suspect was described by police as having a medium complexion and dressed in shorts and dark polo shirt. He was seen by witnesses fleeing the scene with a gun in his hand, police said.

"We are currently conducting an extensive canvass of the area for video and additional witnesses," Deputy Inspector Henry Sautner said in a statement.

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 dozens of men gathered near the site of the shooting, with one of them telling the crowd that it appeared to be a hate crime, even as police said the motive was still unknown.

"We feel really insecure and unsafe in a moment like this," Millat Uddin, an Ozone Park resident told CBS New York. "It's really threatening to us, threatening to our future, threatening to our mobility in our neighborhood, and we’re looking for the justice."

Members of Muslim community attend rally

According to AP, more than 100 people attending a rally at the shooting site Saturday night chanted "We want justice!"

Sarah Sayeed, a member of Mayor Bill de Blasio's staff, serves as a liaison to Muslim communities. She attended the rally and said, "I understand the fear because I feel it myself. I understand the anger. But it's very important to mount a thorough investigation."

Khaled Rahman, who also was there, said he believes the shootings were an attack "against our religion" and he hopes police would increase security around mosques, reports AP.

Shahin Chowdhury, a worshipper at the mosque, said members of the community had felt animosity lately, with people cursing while passing the mosque. He said he had advised fellow community members to be careful while walking around, especially when in traditional clothing.

He called the imam a "wonderful person" with a voice that made his Quran readings especially compelling.

Worshipper Millat Uddin said Akonjee had led the mosque for about two years and was a very pious man, reports AP.

"The community's heart is totally broken," said Uddin, who is not related to Tara. "It's a great misery. It's a great loss to the community and it's a great loss to the society."

Neighbours also described Tara as a pious and thoughtful man who prayed five times a day and went to the mosque. While at home, they said he would water his garden and one next door.

"A very honest, wise man ... (And) a very helpful guy," said neighbor Mohammed Uddin, who is not a relation of Tara's.