New Orleans Mayor Mitch Landrieu is calling in the federal government after the latest daring mass armed robbery at an Uptown establishment.

Three masked men with guns robbed patrons and the register at the Monkey Hill Bar, 6100 Magazine St., about 10:15 p.m. Monday. Although police were not ready to definitively connect that hold-up to strikingly similar ones in recent weeks at the Patois and Atchafalaya restaurants, Landrieu said he sees a “conspiracy” at work. Now he is seeking federal prosecution for the conspirators.

Landrieu appeared at a news conference Tuesday morning packed with City Council members, police commanders and federal officials. In an unusual announcement, U.S. Attorney Kenneth Polite said he had pledged a federal prosecution to the mayor if investigators can establish a pattern in the crimes.

“I can feel your pain,” Landrieu said to the victims of the latest robbery. “I understand the fear. It’s palpable. It’s real. And it’s measurable. Especially when it happens in one neighborhood three times and you can’t seem to find the guys.”

The Monkey Hill robbery seemed ripped straight from the same playbook employed by the restaurant invaders. Three armed men wearing gloves, hoodies and masks entered the bar and took cash from the register and upstairs office, as well as wallets and money from the half-dozen people inside the bar, Police Superintendent Michael Harrison said.

As in the two earlier events, no one was injured.

The three masked robbers were in and out in minutes. One jumped over the bar like a “decathlete,” said Monkey Hill owner Johnny Vodanovich, who had reviewed surveillance video.

Harrison said police were at the bar within five minutes of the robbery.

Vodanovich praised his bartender for showing grace under pressure and police officers for an “exceptionally fast” response. “They were there in a blink,” he said. “The police were thorough, they looked through everything, and they were fantastic.”

Just as he did after the Atchafalaya robbery last week, Harrison said he saw the obvious parallels to earlier incidents. But he said police cannot yet prove that all three incidents are connected. No new details on possible suspects were offered Tuesday.

Even as Vodanovich praised the police response, there were signs that other New Orleanians were not as forgiving.

Speaking at the news conference Tuesday, Councilwoman Susan Guidry said she had been deluged with calls and emails from upset constituents.

Guidry stressed that the City Council has provided funding to the Police Department to hire more officers. “We can’t do anything more than wait for the police officers to be trained,” she said.

Landrieu urged New Orleanians not to panic and noted that crime rates are down significantly from their peaks in the 1990s. Although he has now called on the federal government for help, he also expressed confidence in the NOPD’s ability to catch the perpetrators of the audacious hold-ups.

On Monday, Landrieu and police announced the arrest of a 16-year-old believed to be responsible for a separate string of Uptown armed robberies involving individual victims.

“This Police Department in the last four weeks has arrested and apprehended 14 people that were responsible for 19 armed robberies. That is a really great amount of aggressive work,” Landrieu said. “Unfortunately, these particular guys seem to be really good at what they’re doing.”

As Landrieu pointed out, crime is down significantly in many major categories over the past several years. Police say it has dropped 8 percent this year in the major crime categories reported to the FBI.

Murders and armed robberies, however, have both risen. The city is on track to record 943 armed robberies in 2015, according to crime analyst Jeff Asher, up from 726 in 2011.

It is New Orleans East, not the Uptown neighborhoods targeted in the restaurant and bar robberies, that has been the hardest hit this year. The East’s 7th District had recorded 94 calls about armed robberies with a firearm as of mid-August. There were 72 and 36 such calls in the Uptown 2nd and 6th districts, respectively.

But the Uptown armed robberies, two of them targeting well-known restaurants, have gripped the public’s imagination. Local social media again exploded with commentary after the Monkey Hill heist.

Just down the block from a Monday night homicide in Algiers, one neighbor expressed her alarm — at the armed robberies across the river.

Real estate developer Jim MacPhaille added $10,000 to the Crimestoppers reward pot to catch the perpetrators, if they are found to be responsible for all three incidents. The Louisiana Restaurant Association kicked in another $5,000. The reward total now stands at $30,000, three times the amount offered for information about the May killing of Housing Authority of New Orleans Officer James Bennett.

Harrison said officers would be going door to door at bars and restaurants to offer their owners safety tips and to discuss surveillance cameras. Landrieu, meanwhile, planned to meet with restaurant and hotel owners.

Vodanovich said that even before Monday night’s robbery, he had been considering adding a guard to protect his customers. He planned to open his bar as usual Tuesday night.

“If you don’t, they win,” he said.