NEW YORK — The city anxiously awaited a decision by a grand jury that was weighing whether to charge five officers who unleashed the 50-shot barrage that killed an unarmed black man on his wedding day.The timing of a decision was uncertain because the proceedings are private. The grand jurors went home late yesterday without having decided whether any officers should be indicted, and they were to reconvene today.

The shooting that killed Sean Bell, 23, and wounded two of his companions on November 25 stirred outrage around New York, and officials were bracing for more of the same if the officers avoid charges. Bell was black, as are the other victims; three of the officers are black and two are white.

Mayor Michael Bloomberg, whose community outreach programme went into overdrive this week as months of grand jury presentations wound down, acknowledged that “there will be plenty of people who will disagree no matter what” the decision is.

“If anybody wants to use this as an excuse to cause disruption and violate the law, they will find that our police department will do exactly what they’re trained to do and hired to do,” the mayor warned. “We will make sure that everybody is as safe on the streets before the grand jury rules as afterward.”

The killing of Bell and the wounding of his bachelor party guests, Joseph Guzman and Trent Benefield, raised questions about police tactics and prompted vigils and protests by civil rights activists.

Guzman, Benefield and Nicole Paultre Bell, who was to marry Bell and legally took his name after his death, joined the civil rights leader Rev. Al Sharpton yesterday afternoon in Harlem, appearing on his radio show while awaiting the grand jury’s decision.

“I need justice,” said Guzman, who was shot 16 times and arrived on crutches, his leg in a walking cast.

“I’m praying,” said Paultre Bell.

Sharpton, who has acted as a spokesman of sorts for Bell’s family, said Tuesday that “certain levels of protests and visible actions” would likely arise if there were no indictments, but he said he expected those actions to be peaceful.

“Rather than worry if there’s going to be violence, I would think they’d be worried about the violence that already occurred,” he said in an interview. “Fifty shots is about as violent as you can get.”

Paul Williams, 35, of the Bronx said all five officers should be charged.

“They killed a man for no reason,” Williams said. “That’s my opinion. You don’t shoot and then ask questions. They’re all guilty. They should all be charged.”

Also yesterday, the district attorney’s office said it was aware of someone who came forward to say he was a witness to the shooting and had information about it. But it was unclear whether the grand jury would seek information from the person or continue without it.

The officers testified in ascending order, based on the number of bullets they fired: Detective Paul Headley, who fired one round, and Officer Michael Carey, who fired three, testified first. Officer Marc Cooper fired four shots, and he was followed to the stand by Officer Gescard Isnora, who fired 11 shots. Michael Oliver, who reloaded and fired 31 shots, went on last Friday.

The grand jurors had been instructed to consider several charges: second-degree murder, manslaughter or criminally negligent homicide stemming from Bell’s death; and attempted murder, assault or reckless endangerment in the wounding of Benefield and Guzman.