New York's mayor said he is "deeply disturbed" by the shooting of an unarmed black man by police but said he would support the city's police chief.
Mr Bloomberg said he would make information public as he got it
After talks with Police Commissioner Ray Kelly, Michael Bloomberg pledged a thorough investigation, saying it was unacceptable that 50 shots were fired.
Sean Bell, 23, was killed on Saturday when officers opened fire as he left a strip club on the eve of his wedding.
It is alleged police began firing after his car hit an unmarked police vehicle.
Two of Mr Bell's friends, who were travelling in the car, were also injured.
Joseph Guzman was hit by at least 11 bullets and is in a critical condition. Trent Benefield was hit three times and is in a stable condition.
No weapons were found on the three men or in their car, nor have any charges been made.
Five officers have been placed on administrative duties during an inquiry into the shooting outside the Kalua Club, at the end of Mr Bell's stag night celebrations.
'Fill in the blanks'
Following the talks with the city's police chief and community leaders, Mr Bloomberg said: "I can tell you that it is to me unacceptable or inexplicable how you can have 50-odd shots fired, but that is up to the investigation to find out what really happened."
Mr Bloomberg said he was not going to speculate or "fill in the blanks" but would make information public as soon as he had it.
Reverend Al Sharpton, a prominent civil rights activist, called it a "very candid, a very blunt meeting".
He said the message to the mayor was: "This city must show moral outrage that 50 shots were fired on three unarmed men."
Timothy Thomas, 2001: Unarmed black teenager shot by white officer in Cincinnati while fleeing. Death sparked days of rioting in city
Patrick Dorismond, 2000: Unarmed black man killed in bungled drugs sting in New York, in a death which drew protests
Amadou Diallo, 1999: West African immigrant killed when white police mistook his wallet for gun. Four officers acquitted; family given $3m
Rodney King, 1991: Black man badly beaten by LA police after resisting arrest for speeding, in videotaped attack. Acquittal of officers led to riots in 1992. Mr King given $3.8m
The talks at City Hall come a day after several hundred people held a rally for Mr Bell, during which protesters called for Commissioner Kelly's resignation.
New York police have faced criticism over other shootings of unarmed black men in recent years.
According to Commissioner Kelly, the club was under surveillance because of its long history of weapons complaints, drug-dealing and prostitution.
He said an undercover officer at the club had reported that the men were in a group involved in a dispute with another person outside the club.
The officer had reportedly called his colleagues saying he feared a gun would be produced.