Some nights, the corner of N. 11th and Knox avenues in Minneapolis takes on the bustle of an open-air bazaar, without a shopkeeper in sight.

A car’s radio blares old-school soul tunes well into the early morning, neighbors say. Fights are common and drug dealers peddling marijuana and heroin don’t bother hiding their transactions anymore, they add.

A few weeks ago, Ellanor Abdullah got so fed up with the noise, trash and traffic that she went outside to confront the group hanging out next to a grassy vacant lot in the Near North neighborhood. They cursed her out, she says.

“They’re out there 24 hours a day, day and night,” Abdullah said. “I’ve been there 34 years and never had a problem until this group planted themselves there.”

More than once, she says, she has looked out of her window to see what appeared to be a drug deal: A car will pull up to the lot, honk, and wait until someone runs up to either the driver or passenger side. After cash changes hands, the car typically drives off, according to Abdullah.

After many sleepless nights, neighbors started calling and e-mailing Fifth Ward Council Member Jeremiah Ellison’s office to demand that something be done. Ellison visited the scene, then centered at the corner of 12th and Knox, to see the teeming crowds for himself. Within a few days a mobile police camera appeared at the corner; police patrols also picked up. For a while, the disturbances subsided, only to return in recent months, this time a block south.

Court records show that authorities have been keeping an eye on suspected narcotics dealers in the area for months. Gang members are said to be using a residence at 12th and Knox as a stash house, to store guns and drugs. On at least one occasion, investigators sent an informant to the house to attempt a controlled buy, the records show.

Since May 7, police have been called to that block at least 91 times — an average of more than once a day — mostly for suspected drug activity and to investigate reports of suspicious people and vehicles. One night, three squad cars parked a block away and pointed their headlights at the lot, scattering the crowds of young people for several hours. The next night, the crowds were back.

Ellison did not respond to a request seeking comment. Department spokeswoman Sgt. Darcy Horn said police were “very aware of the problems occurring on the lot,” and had beefed up patrols in the area.

“We are working with our block club leaders in the area and the property owners of the houses and apartments nearby regarding trespassing as well,” Horn said in a statement.

Sasha Cotton, director of the city’s newly formed Office of Violence Prevention, said Minneapolis officials have gotten complaints about the property, but are still trying to determine how best to deal with it.

“It is definitely an area of concern that has been raised by community members,” she said, adding: “We don’t want to criminalize something if that’s inappropriate — we don’t have enough information to know what it is yet.”

The problem has been around for years, hopscotching from block to block every time police try to get a handle on the criminal activity, said resident Lisa Delgado.

“All they do is move the problem; they can’t solve the problem,” said Delgado, who has shooed junkies from her front yard, where they sometimes smoke or shoot up after buying drugs nearby. “Once again, you can’t let your kids go outside because you don’t know what they’re going to do.”

Delgado said she has seen men stopping to urinate on nearby houses, and regularly witnesses people engaged in sex acts, sometimes in the middle of the road, in broad daylight. The former Washington, D.C., cop wishes that more attention were paid to the effect the heavy drug traffic had on the neighborhood of working-class families.

Some residents worry about calling police on the mostly black crowds either out of fear of being seen as stereotyping or because it might invite a heavy-handed police response.

One man who lives nearby, but declined to give his name, said that some neighbors have been intimidated into silence, worried their car windows will be smashed if they call police. The group, he says, has made itself quite at home, dragging a couch and a BBQ grill out onto the otherwise well-maintained lot, which is privately owned.

When a reporter visited the block on a recent weeknight, the scene was low-key, with only a handful of people hanging out next to a retaining wall that runs along the lot, and no music playing. Neighbors said a small group of troublemakers had dispersed earlier that night.

By 1 a.m., a 911 call about an earlier disturbance at the corner had been pending for more than a half-hour, as all of the precinct’s roughly dozen available squad cars were tied up responding to a series of shootings.

But most nights are anything but quiet, according to Abdullah.

“A few times I’ve been up all night — I can’t sleep, because even with the windows closed, they’re going in and out, in and out, all night,” she said.