BALTIMORE - As dusk crept over Collington Square Park, in east Baltimore, the children's chatter of questions began.
"What time is my curfew?" "What if I'm out with my brother and he's 18?" "If I hide, can I still stay out and play?"
A 23-year-old man with thin, cascading braids who goes by the name Dreads interrupted the chorus of voices: "It's 8:05! You all have 55 minutes left!"
A new youth curfew law, among the strictest in the nation, took effect in Baltimore on Friday night. It requires unaccompanied children under the age of 14 to be indoors by 9 p.m. and for 14, 15 and 16-year-olds to be indoors by 10 p.m. on weekdays and 11 p.m. on weekends and during the summer.
Children found out on the streets can be picked up by police and escorted to one of two recreational centers set up by the city until parents or guardians pick them up.
Mayor Stephanie Rawlings-Blakes says the rules will help keep kids out of harm's way in a city that has long struggled with high crime. But civil liberties groups, including the American Civil Liberties Union of Maryland, say the rules are too vague and make negative interactions between police and children all but inevitable.
"I think there is a widely acknowledged lack of trust between members of the public and the police department in Baltimore. Discussion of this falls against that backdrop," said Sonia Kumar, an ACLU staff attorney.
She said she was also concerned about how police would react if they stop a child who is not carrying a photo identification, or if the child attempts to run away.
Other critics noted that the rec halls that were serving as collection centers for the kids by night were closed for activities and events during the day.
Baltimore, which served as the staging ground for the celebrated HBO police drama "The Wire," has one of the highest rates of violent crime of any U.S. city, with 218 homicides reported in 2012, according to FBI data.
But there are signs that crime in this city of some 625,000 is starting to ebb. The number of murders this year is down 14 percent compared to the same period last year.
While the curfew attracted strong opposition at a public forum last week, many parents approached on Friday night said they thought it was a good idea.
"A lot goes on at night that they don't need to be involved with," said Alyssa Jackson, 20, as she tended to her 9-month-old daughter Madison on one knee. Jackson said her mother had set a similar curfew for her as a child, and she planned to do the same for her own daughter.
Jackson's friend, Emmanuel Lawson, a fellow Baltimore native, nodded his head in agreement. "Honestly, it just eliminates the possibility of people acting a fool," he said of the curfew.
But Kim Johnson, a single mother of five boys who works a night shift doing custodial work, wasn't so sure.
"What if the baby gets sick in the middle of the night and my 16-year-old needs to go to the store to get something?" said Jackson, 34, as she pushed her child on a swing shortly before the curfew took effect.
She said she was especially worried about the city's threat of fining parents up to $500 if children are found unattended.
For hours after the curfew went into effect, the two recreation centers set up by the city were mostly quiet.
At one point, a woman arrived at the center on the city's west side saying she had come to collect her 11-year-old grandson.
"I think it's good," she said of the curfew. "The kids shouldn't be out on the streets when it gets dark."
Writing by Edith Honan; Editing by Frances Kerry