Violent gang members are suspected of killing at least four high school teenagers in one suburban New York community in the last month, kicking off a distressing start to the new school year.

The school year at Brentwood High School on Long Island has started with funerals, fear and frustrations as the students have been victims of the suspected gang violence.

On Sept. 13, the day before her 16th birthday, Nisa Mickens' brutally beaten body was found on a tree-lined street in Brentwood. A day later, the beaten body of her lifelong friend, 16-year-old Kayla Cuevas, was discovered in the wooded backyard of a nearby home. The teenagers had been inseparable and shared an interest in basketball.

Days later, police discovered the skeletal remains of 19-year-old Oscar Acosta and 15-year-old Miguel Garcia-Moran in a remote industrial area of the town. Acosta had been missing since May, and Garcia-Moran vanished in February.

Students have expressed fears of walking alone in their community and school officials have warned them about wearing clothing that could offend potential gang members.

Alexis Portillo, 16, was devastated when he learned of the killings: "Like, who else is going to be next, you know?"

One Brentwood teen who wouldn't give his name, saying he feared gang retaliation, said many students are nervous.

"They don't play around. If they don't like you and if you do something to them, they will come after you," he said. "I'm not going to walk anywhere. We're definitely more cautious about that. I don't go out at night anymore."

A law enforcement source told the Associated Press that the notorious Salvadoran gang MS-13 is suspected of committing the unspeakable horrors. Police haven’t made any arrests.

The violent street gang has made the Long Island neighborhood home. MS-13 gang members are suspected of killing at least 30 people on Long Island since 2010.

Suffolk County Police Commissioner Timothy Sini says detectives are optimistic about arrests. A "violent known gang member" was in federal custody, he said, but the arrest papers and charges are under seal and no one is saying if that suspect is tied to any of the killings.

Last week, investigators searched a shuttered state psychiatric hospital for additional victims but came up empty.

All this leaves a community on edge.

In Brentwood, police are releasing few details about their investigation into students' deaths.

Abraham Chaparro, Garcia-Moran's stepfather, said he was last seen heading off to meet some friends. He said his stepson, who emigrated from Ecuador two years ago, liked cars, soccer and girls.

"He had a girlfriend in every corner. He was good-looking," Chaparro said. "I don't understand how this happened. It's a mystery."

A large photo of the boy smiling in a white suit and black bow tie sat at the front of a funeral home chapel as mourners paid respects this past week.

Maria Arias spent days going door to door looking for her son, Oscar, after he disappeared while reportedly going to a nearby park to play soccer.

Brentwood school officials said a freshman walking to a bus stop with a light blue T-shirt in his hand was stopped last week by a group in a car. The driver demanded the shirt, which was set on fire; the student was told not to wear that color again. Curtis Sliwa, founder of the New York City-based Guardian Angels, a neighborhood patrol group that has now started patrols in Brentwood, said blue is an MS-13 color.

School officials advised in a letter to parents that "children not wear clothing that could be considered to be gang-related."

Monique Darrisaw-Akil, assistant superintendent for secondary education, conceded that "students sometimes get involved in things that are not in their best interest or in the best interest of the school community, so we try to be as proactive, and provide interventions."

The Associated Press contributed to this report.