|Muslims in New York have frequently protested against the police department's surveillance tactics [File: EPA]
US civil rights groups have called on the New York attorney-general to investigate the city's police department, after leaked documents showed police recommended increasing surveillance of Muslim Shia mosques based on their religion.
In a letter to Attorney-General Eric Schneiderman, 33 rights organisations urged him to open a probe into the New York police department's surveillance operations.
Schneiderman's office did not immediately comment on the letter.
The move comes after the AP news agency revealed its investigation into the surveillance techniques, which it said monitored entire neighbourhoods and built databases about life in Muslim communities.
A May 2006 report addressed to the police commissioner, Raymond Kelly, recommended increased spying at mosques and an assessment of the region's Palestinian community to look for potential terrorists, AP said.
The report, entitled "US-Iran Conflict: The Threat to New York City", made a series of recommendations to Kelly, including: "Expand and focus intelligence collections at Shia mosques."
It included a list of mosques and community organisations, extending from southern New Jersey to Connecticut.
The police department's operating rules prohibit it from basing investigations on religion.
The department also says it follows guidelines set by the FBI, which would prohibit many of the steps recommended in the report.
The report appeared to contradict previous statements from Kelly and Mayor Michael Bloomberg, who have insisted that police only follow legitimate leads and do not conduct preventative surveillance in ethnic communities.
The film appearance by Commissioner Kelly angered New York's Muslim community [File: Al Jazeera]
On Thursday, Kelly downplayed the significance of the 2006 report, saying it was a "contingency plan" for military conflict between the US and Iran.
However, AP noted that such language does not exist anywhere in the document.
Even before AP published the document, Kelly faced criticism from Muslim groups who were angry about a controversial movie about Muslims entitled "The Third Jihad", which was shown at New York police training sessions.
Muslim activists say the movie, in which Kelly appears briefly, vilifies American-Muslims and portrays them as a threat.
"We are beginning to wonder whether NYPD officials believe American Muslims have any constitutional rights that need be respected," Cyrus McGoldrick, a spokesman for the Council on American-Islamic Relations, a Muslim civil liberties group, said in a statement.
"Each new revelation of NYPD targeting of the Muslim community without evidence of wrongdoing paints a picture of a department that has little regard for legal prohibitions on ethnic and religious profiling."
More than 100 protesters gathered near police headquarters in New York on Friday, chanting "Don't be afraid, stand for justice!" in a protest against the police tactics.