City leaders and law enforcement officials yesterday weighed recommending earlier city curfews for young people after the "flash mob" Saturday night on South Street terrified onlookers and forced shops and restaurants to close early.

"Nobody wants to go that route," said Dave Hammond, executive director of the South Street Head House District, "but you can't continue with the flash mobs the way they've been."

Law enforcement officials embraced the idea.

"I don't make the law, but I would love to see something like that," said Deputy Police Commissioner Richard Ross. "It would help us immensely."

District Attorney Seth Williams also said he would support the earlier curfews.

Currently, minors under the age of 18 are required to be off city streets by 10:30 p.m. on weekdays and midnight on weekends.

But after thousands of teenagers and young adults swarmed the South Street corridor between Second and Broad Streets late Saturday, Hammond suggested a weekend curfew of 9:30 or 10, which he said could have greatly reduced Saturday night's crowds.

Still, he said, "It's a Catch-22. You don't want to drive away the kids who in the future are going to be customers."

Other city officials sought to tamp down public fears and worried that media reports might deal a blow to businesses already suffering during a weak economy.

"The timing couldn't be worse with the retail environment not doing well to begin with," said Councilman Frank DiCicco, whose district includes the South Street corridor. "People could become unemployed as a result of this reckless behavior."

DiCicco said he would ask Mayor Nutter today to sign an executive order that would instantly put the new curfews into effect.

"Legislation would take too long," DiCicco said. "My constituents are frightened and worried this could go on for the spring and summer months."

Nutter and other officials, meanwhile, warned teens that illegal behavior would not be tolerated.

"It's one thing to get together. It's another thing to cause disturbance or engage in property damage or physical assault," Nutter said.

Although he offered no details, Nutter said the city would soon announce a new strategy for coping with the sudden gatherings.

"We want further checks in place as soon as possible, but we also want people to check their own behavior," he said.

He called on parents to monitor their children's whereabouts, and to inform police if they learn of a flash mob in the making.

Police said Saturday night's flash mob could have ended in disaster if a parent had not seen a text message on a teen's cell phone and called 911.

Ross, the deputy commissioner, said police were able to muster a sizable show of force after receiving the alert.

"If we had not gotten that phone call, there probably wouldn't have been enough police officers," Ross said. "But because we got that call, we did."

Everett Gillison, deputy mayor for public safety, stressed that the city was taking the flash mobs seriously and predicted that the phenomenon would fade in time, particularly if public hysteria can be avoided.

"I think this is a fad. I do not think this is something we should be frightened about," Gillison said.

While business owners and some nervous adults might prefer to see every large gathering of teens immediately dispersed, Gillison noted there was nothing illegal about socializing in a public place.

"There is the right to free assembly in this country. People have the constitutional right to be an idiot," Gillison said.

So-called flash mobs have bedeviled the city over the past year. Several people were injured May 30 when at least 100 teens converged at Broad and South Streets. In that incident, a 54-year-old man riding his bicycle home from work was critically injured when he beaten by a group of young men. A cabdriver was assaulted and robbed at 12th and South, and two people were pulled from a vehicle on Broad Street, assaulted and robbed.

Mobs of teens have disrupted Center City three times in the past three months. On Dec. 18, students from several city high schools responded to a call via Facebook to gather at the Gallery food court, police said. When turned away by security, large groups of the teens then swarmed west, randomly attacking pedestrians on nearby Center City streets.

In a Feb. 16 melee, 150 teens spilled out of the Gallery during rush hour and rampaged several blocks away through Macy's, where they knocked down pedestrians and damaged displays.

After fights among young people broke out March 3 near Broad Street, police made 28 arrests and charged several participants with felony rioting.