Montgomery County officials proposed a curfew Tuesday that would ban youths younger than 18 from public places late at night, citing an increase in gang activity and violence among teens.

Police and some government officials said many teenagers involved in late-night trouble are from Montgomery, but they are concerned that curfews in the District and Prince George’s County are pushing teens across the county line.

“Kids tend to go where they have the area of least resistance,” Montgomery County Executive Isiah Leggett (D) said of his county’s lack of a curfew. “We sort of stand alone. As a result you get the residual effect of people going where the opportunities are.”

Police point to one recent incident in which as many as 70 young people, including suspected gang members, gathered in downtown Silver Spring during the July 4 weekend. Many arrived on bus or Metro, police said. Several fights broke out, and one ended with the stabbing of a teenage girl, officials said. She survived.

“I don’t want to wait until they have escalated completely out of hand,” Leggett said.

Neither Leggett’s office nor the police department could provide statistics Tuesday on recent juvenile crime trends. From 2007 until 2010, the most recent gang-data available, gang-related incidents and crimes decreased in the county each year — from 507 to 232.

But police officers on the streets report they are encountering problems with teens who hang out in public areas into the early morning hours, officials said.

“We’re seeing an uptick,” said Assistant Police Chief Wayne Jerman.

An area of prime concern is one of Montgomery’s most bustling spots on weekend nights, downtown Silver Spring, with its movie theaters, wide sidewalks and restaurants. Leaders in Silver Spring, and families who gather there, take pride in the diversity of the crowd and, for the most part, its good behavior.

But officers also say that as nights wear on, particularly past 10, the crowd changes.

“It’s challenging,” said Capt. Donald Johnson, commander of the police district in and around Silver Spring. “I often compare it with the boardwalk in Ocean City at the time of night.”

Police stressed that the curfew would be valuable in other hot spots in the county beyond Silver Spring. It would ban people younger than 18 from public places after midnight on Friday and Saturday, and after 11 p.m. on other nights. They could be back out at 5 a.m.

The legislation provides exceptions — travel to a job and emergencies, for example.

Under the proposal, youths picked up would be taken to a police station and released to a parent or guardian. Later, a court could order community service for the child. And parents could be required to take parenting classes.

In Prince George’s County, youths under 17 cannot be in public places after midnight on weekends and after 10 p.m. on other nights. In the District, youths under 17 cannot be in public places after midnight on weekends and after 11 p.m. on other nights. The cutoff extends to midnight for all nights during the summer.

Alex Porter, 16, a student at Sherwood High School in Sandy Spring who was out one recent night for dinner with a friend and his mother, said he thinks the legislation is unnecessary. He and his friends, he said, don’t wander the streets at night or get involved in fights.

The curfew is “not like a bad idea, and I understand the motivation, but I still think it should stay within the family,” Porter said. But, he admitted, “I know there’re people at my school who will do things like that.”

Most kids well-behaved

Council member Marc Elrich (D-At Large) said he wants to study the idea further.

“Curfews are tough, because 99 percent of kids don’t do anything wrong,” Elrich said, but added, “The last thing we need is Silver Spring or Wheaton getting a reputation as a place where gangs hang out.”

Montgomery County Council President Valerie Ervin (D-Silver Spring) introduced the curfew legislation Tuesday at Leggett’s request. She said that the council would study whether the curfew should be applied throughout the county and, if so, how. If a county curfew is passed, for example, the jurisdictions of Rockville and Gaithersburg might have to implement similar legislation to avoid being curfew-free zones.

Given the time needed to study the measure, a curfew probably would not go into effect until at least September, council members said.

Teenagers and young adults interviewed in Silver Spring and Bethesda over the past two days expressed divergent opinions.

Elisabeth Cass, 20, who was at the food court at the Westfield Montgomery Shopping Mall in Bethesda on Tuesday afternoon, said a curfew would have a “tremendous” effect in the area. When she was younger, Cass said, she and her friends partied at night, and some of them drank until they blacked out.

“I was a crazy high school kid, but I’m not in high school anymore,” Cass said.

Also at the food court was Shaine Cohen, 13, and a friend, who described themselves as “nocturnal” and questioned the wisdom of the curfew. At sleepovers, they said, they sometimes get bored and walk outside late at night.

“Maybe I can’t go to sleep, so I walk around,” Cohen said.